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Joel D. Richter - One of the best experts on this subject based on the ideXlab platform.
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Cytoplasmic Polyadenylation Element Binding Proteins in Development, Health, and Disease
Annual review of cell and developmental biology, 2014Co-Authors: Maria Ivshina, Paul Lasko, Joel D. RichterAbstract:The Cytoplasmic Polyadenylation Element binding (CPEB) proteins are sequence-specific mRNA binding proteins that control translation in development, health, and disease. CPEB1, the founding member of this family, has become an important model for illustrating general principles of translational control by Cytoplasmic Polyadenylation in gametogenesis, cancer etiology, synaptic plasticity, learning, and memory. Although the biological functions of the other members of this protein family in vertebrates are just beginning to emerge, it is already evident that they, too, mediate important processes, such as cancer etiology and higher cognitive function. In Drosophila, the CPEB proteins Orb and Orb2 play key roles in oogenesis and in neuronal function, as do related proteins in Caenorhabditis elegans and Aplysia. We review the biochemical features of the CPEB proteins, discuss their activities in several biological systems, and illustrate how understanding CPEB activity in model organisms has an important impa...
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Dendritic GluN2A synthesis mediates activity-induced NMDA receptor insertion.
The Journal of neuroscience : the official journal of the Society for Neuroscience, 2013Co-Authors: Sharon A. Swanger, Joel D. Richter, Gary J. BassellAbstract:Long-term synaptic plasticity involves changes in the expression and membrane insertion of cell-surface proteins. Interestingly, the mRNAs encoding many cell-surface proteins are localized to dendrites, but whether dendritic protein synthesis is required for activity-induced surface expression of specific proteins is unknown. Herein, we used microfluidic devices to demonstrate that dendritic protein synthesis is necessary for activity-induced insertion of GluN2A-containing NMDA receptors in rat hippocampal neurons. Furthermore, visualization of activity-induced local translation of GluN2A mRNA and membrane insertion of GluN2A protein in dendrites was directly observed and shown to depend on a 3' untranslated region Cytoplasmic Polyadenylation Element and its associated translation complex. These findings uncover a novel mechanism for Cytoplasmic Polyadenylation Element-mediated posttranscriptional regulation of GluN2A mRNA to control NMDA receptor surface expression during synaptic plasticity.
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Cytoplasmic Polyadenylation and Cytoplasmic Polyadenylation Element-dependent mRNA regulation are involved in Xenopus retinal axon development
Neural Development, 2009Co-Authors: Andrew C Lin, Joel D. Richter, Chien-ling Lin, Chin Lik Tan, Laure Strochlic, Yi-shuian Huang, Christine E HoltAbstract:Background Translation in axons is required for growth cone chemotropic responses to many guidance cues. Although locally synthesized proteins are beginning to be identified, how specific mRNAs are selected for translation remains unclear. Control of poly(A) tail length by Cytoplasmic Polyadenylation Element (CPE) binding protein 1 (CPEB1) is a conserved mechanism for mRNA-specific translational regulation that could be involved in regulating translation in axons. Results We show that Cytoplasmic Polyadenylation is required in Xenopus retinal ganglion cell (RGC) growth cones for translation-dependent, but not translation-independent, chemotropic responses in vitro , and that inhibition of CPE binding through dominant-negative interference severely reduces axon outgrowth in vivo . CPEB1 mRNA transcripts are present at low levels in RGCs but, surprisingly, CPEB1 protein was not detected in eye or brain tissue, and CPEB1 loss-of-function does not affect chemotropic responses or pathfinding in vivo . UV cross-linking experiments suggest that CPE-binding proteins other than CPEB1 in the retina regulate retinal axon development. Conclusion These results indicate that Cytoplasmic Polyadenylation and CPE-mediated translational regulation are involved in retinal axon development, but that CPEB1 may not be the key regulator of Polyadenylation in the developing retina.
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Cytoplasmic Polyadenylation and Cytoplasmic Polyadenylation Element-dependent mRNA regulation are involved in Xenopus retinal axon development
Neural development, 2009Co-Authors: Andrew C Lin, Joel D. Richter, Chien-ling Lin, Chin Lik Tan, Laure Strochlic, Yi-shuian Huang, Christine E HoltAbstract:Translation in axons is required for growth cone chemotropic responses to many guidance cues. Although locally synthesized proteins are beginning to be identified, how specific mRNAs are selected for translation remains unclear. Control of poly(A) tail length by Cytoplasmic Polyadenylation Element (CPE) binding protein 1 (CPEB1) is a conserved mechanism for mRNA-specific translational regulation that could be involved in regulating translation in axons. We show that Cytoplasmic Polyadenylation is required in Xenopus retinal ganglion cell (RGC) growth cones for translation-dependent, but not translation-independent, chemotropic responses in vitro, and that inhibition of CPE binding through dominant-negative interference severely reduces axon outgrowth in vivo. CPEB1 mRNA transcripts are present at low levels in RGCs but, surprisingly, CPEB1 protein was not detected in eye or brain tissue, and CPEB1 loss-of-function does not affect chemotropic responses or pathfinding in vivo. UV cross-linking experiments suggest that CPE-binding proteins other than CPEB1 in the retina regulate retinal axon development. These results indicate that Cytoplasmic Polyadenylation and CPE-mediated translational regulation are involved in retinal axon development, but that CPEB1 may not be the key regulator of Polyadenylation in the developing retina.
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CPEB : a life in translation
Trends in biochemical sciences, 2007Co-Authors: Joel D. RichterAbstract:Nearly two decades ago, Xenopus oocytes were found to contain mRNAs harboring a small sequence in their 3′ untranslated regions that control Cytoplasmic Polyadenylation and translational activation during development. This Cytoplasmic Polyadenylation Element (CPE) is the binding platform for CPE-binding protein (CPEB), which promotes Polyadenylation-induced translation. Since then, the biochemistry and biology of CPEB has grown rather substantially: mechanistically, CPEB nucleates a complex of factors that regulates poly(A) elongation through, of all things, a deadenylating enzyme; biologically, CPEB mediates many processes including germ-cell development, cell division and cellular senescence, and synaptic plasticity and learning and memory. These observations underscore the growing complexities of CPEB involvement in cell function.
Brian M. Lee - One of the best experts on this subject based on the ideXlab platform.
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the c terminal region of Cytoplasmic Polyadenylation Element binding protein is a zz domain with potential for protein protein interactions
Journal of Molecular Biology, 2013Co-Authors: Daniel Merkel, Bryce Hilburn, Sarah Wells, Fatima Elazzouzi, Gabriela C Perezalvarado, Brian M. LeeAbstract:Cytoplasmic Polyadenylation Element binding protein (CPEB) provides temporal and spatial control of protein synthesis required for early development and neuronal synaptic plasticity. CPEB regulates protein expression by inhibiting Polyadenylation of selected mRNA transcripts, which prevents binding of the ribosome for protein synthesis. Two RNA recognition motif domains and a C-terminal binuclear zinc-binding domain are required for mRNA binding, but the zinc-binding domain is not required for sequence-specific recognition of the targeted mRNA transcript. The structure and function of the zinc-binding domain of CPEB are unknown. The C-terminal region of CPEB may participate in assembly of the ribonucleoprotein complex that includes the scaffold protein, Symplekin, and the cleavage and Polyadenylation specificity factor. Sumoylation of Symplekin is required for Polyadenylation, and both cleavage and Polyadenylation specificity factor and poly(A) polymerase are sumoylated. The foreshortened poly(A) tail is maintained by poly(A) ribonuclease, which associates with CPEB. While zinc-binding domains are renowned for nucleic acid recognition, binuclear zinc-binding structural motifs, such as LIM (Lin-11, Isl-1, Mec-3), RING (really interesting new gene), PHD (plant homeodomain) and ZZ (ZZ-type zinc finger) domains, participate in protein-protein interactions. Here, we report the solution structure of the C-terminal zinc-binding domain of CPEB1 (CPEB1-ZZ), which has a cross-braced zinc binding topology. The structural similarity to other ZZ domains suggests that the CPEB1-ZZ domain recruits sumoylated proteins during assembly of the ribonucleoprotein complex prior to mRNA export from the nucleus.
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The C-Terminal Region of Cytoplasmic Polyadenylation Element Binding Protein Is a ZZ Domain with Potential for Protein–Protein Interactions
Journal of molecular biology, 2013Co-Authors: Daniel Merkel, Bryce Hilburn, Sarah Wells, Fatima Elazzouzi, Gabriela C. Pérez-alvarado, Brian M. LeeAbstract:Cytoplasmic Polyadenylation Element binding protein (CPEB) provides temporal and spatial control of protein synthesis required for early development and neuronal synaptic plasticity. CPEB regulates protein expression by inhibiting Polyadenylation of selected mRNA transcripts, which prevents binding of the ribosome for protein synthesis. Two RNA recognition motif domains and a C-terminal binuclear zinc-binding domain are required for mRNA binding, but the zinc-binding domain is not required for sequence-specific recognition of the targeted mRNA transcript. The structure and function of the zinc-binding domain of CPEB are unknown. The C-terminal region of CPEB may participate in assembly of the ribonucleoprotein complex that includes the scaffold protein, Symplekin, and the cleavage and Polyadenylation specificity factor. Sumoylation of Symplekin is required for Polyadenylation, and both cleavage and Polyadenylation specificity factor and poly(A) polymerase are sumoylated. The foreshortened poly(A) tail is maintained by poly(A) ribonuclease, which associates with CPEB. While zinc-binding domains are renowned for nucleic acid recognition, binuclear zinc-binding structural motifs, such as LIM (Lin-11, Isl-1, Mec-3), RING (really interesting new gene), PHD (plant homeodomain) and ZZ (ZZ-type zinc finger) domains, participate in protein-protein interactions. Here, we report the solution structure of the C-terminal zinc-binding domain of CPEB1 (CPEB1-ZZ), which has a cross-braced zinc binding topology. The structural similarity to other ZZ domains suggests that the CPEB1-ZZ domain recruits sumoylated proteins during assembly of the ribonucleoprotein complex prior to mRNA export from the nucleus.
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Solution Structure of the Binuclear Zinc Finger of Cytoplasmic Polyadenylation Element Binding Protein (CPEB)
Biophysical Journal, 2012Co-Authors: Brian M. Lee, Daniel Merkel, Bryce Hilburn, Sarah WellsAbstract:Synaptic plasticity, the experience dependent variation in the strength of a synapse, is a means of encoding memory through a network of specific connections between neurons. Cytoplasmic Polyadenylation Element binding protein (CPEB) is a key factor in establishing the synaptic mark through translational regulation of protein synthesis. A neuronal isoform (CPEB1) participates in sequence specific recognition of a uracil-rich Cytoplasmic Polyadenylation Element (CPE) within the 3’ UTR of mRNA. The C-terminal region of CPEB1 binds to mRNA utilizing three structured domains including two RNA recognition motifs and a zinc finger domain. We have characterized the structure of the binuclear zinc finger domain by NMR spectroscopy.
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Structural Analysis of the C-Terminal RNA Binding Domain of CPEB3
Biophysical Journal, 2011Co-Authors: Bryce Hilburn, Daniel Merkel, Sarah Wells, Brian M. LeeAbstract:Cytoplasmic Polyadenylation Element binding protein isoform 3 (CPEB3) is a translational regulatory protein. There are four isoforms of CPEB. CPEB1 binds to a uracil rich Cytoplasmic Polyadenylation Element (CPE) sequence in the 3’UTR of mRNA and upon phosphorylation switches from an inhibitor to an activator of translation through regulation of Polyadenylation. CPEB3 does not promote Polyadenylation nor does it bind to the CPE sequence. Rather, CPEB3 recognizes a structured RNA motif in the 3’UTR and inhibits translation. CPEB comprises an N-terminal kinase-binding region, two RNA recognition motifs that function in molecular recognition and a C-terminal zinc finger that doe not influence specificity, but is required for binding RNA. Our initial research is focused on the recognition of a structured mRNA by CPEB3 for comparison with parallel studies of CPEB1 bound to a single stranded CPE sequence. We have cloned, expressed and purified the isotope labeled RNA binding region of CPEB3. Preliminary structural studies and assays of the RNA binding activity are presented.
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Structural Characterization of the Zinc Finger Domain of Cytoplasmic Polyadenylation Element-Binding Protein
Biophysical Journal, 2011Co-Authors: Daniel Merkel, Bryce Hilburn, Sarah Wells, Stephanie Geiser, Haley Hoover, Oluwatobi Ajoku, Brian M. LeeAbstract:Cytoplasmic Polyadenylation Element-binding protein (CPEB) is an important factor in translational regulation of oogenesis, cellular senescence and synaptic plasticity. It does this by regulating a poly(A) tail elongation through interactions with a number of other proteins. The region of mRNA that CPEB binds to is a uracil rich region known as the Cytoplasmic Polyadenylation Element (CPE). The carboxy terminal region of CPEB is composed of three regions that are required for CPE recognition and binding within the 3’ UTR of mRNA. It has two RNA binding domains and a zinc finger motif. The zinc finger region contains six cysteine and two histidine amino acids that are highly conserved throughout many species. The conserved residues suggest the presence of a zinc finger structure containing two zinc ions. The zinc finger region of CPEB does not seem to be homologous with any know zinc fingers. We are currently in the process of structural characterization using NMR techniques.
Daniel Merkel - One of the best experts on this subject based on the ideXlab platform.
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the c terminal region of Cytoplasmic Polyadenylation Element binding protein is a zz domain with potential for protein protein interactions
Journal of Molecular Biology, 2013Co-Authors: Daniel Merkel, Bryce Hilburn, Sarah Wells, Fatima Elazzouzi, Gabriela C Perezalvarado, Brian M. LeeAbstract:Cytoplasmic Polyadenylation Element binding protein (CPEB) provides temporal and spatial control of protein synthesis required for early development and neuronal synaptic plasticity. CPEB regulates protein expression by inhibiting Polyadenylation of selected mRNA transcripts, which prevents binding of the ribosome for protein synthesis. Two RNA recognition motif domains and a C-terminal binuclear zinc-binding domain are required for mRNA binding, but the zinc-binding domain is not required for sequence-specific recognition of the targeted mRNA transcript. The structure and function of the zinc-binding domain of CPEB are unknown. The C-terminal region of CPEB may participate in assembly of the ribonucleoprotein complex that includes the scaffold protein, Symplekin, and the cleavage and Polyadenylation specificity factor. Sumoylation of Symplekin is required for Polyadenylation, and both cleavage and Polyadenylation specificity factor and poly(A) polymerase are sumoylated. The foreshortened poly(A) tail is maintained by poly(A) ribonuclease, which associates with CPEB. While zinc-binding domains are renowned for nucleic acid recognition, binuclear zinc-binding structural motifs, such as LIM (Lin-11, Isl-1, Mec-3), RING (really interesting new gene), PHD (plant homeodomain) and ZZ (ZZ-type zinc finger) domains, participate in protein-protein interactions. Here, we report the solution structure of the C-terminal zinc-binding domain of CPEB1 (CPEB1-ZZ), which has a cross-braced zinc binding topology. The structural similarity to other ZZ domains suggests that the CPEB1-ZZ domain recruits sumoylated proteins during assembly of the ribonucleoprotein complex prior to mRNA export from the nucleus.
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The C-Terminal Region of Cytoplasmic Polyadenylation Element Binding Protein Is a ZZ Domain with Potential for Protein–Protein Interactions
Journal of molecular biology, 2013Co-Authors: Daniel Merkel, Bryce Hilburn, Sarah Wells, Fatima Elazzouzi, Gabriela C. Pérez-alvarado, Brian M. LeeAbstract:Cytoplasmic Polyadenylation Element binding protein (CPEB) provides temporal and spatial control of protein synthesis required for early development and neuronal synaptic plasticity. CPEB regulates protein expression by inhibiting Polyadenylation of selected mRNA transcripts, which prevents binding of the ribosome for protein synthesis. Two RNA recognition motif domains and a C-terminal binuclear zinc-binding domain are required for mRNA binding, but the zinc-binding domain is not required for sequence-specific recognition of the targeted mRNA transcript. The structure and function of the zinc-binding domain of CPEB are unknown. The C-terminal region of CPEB may participate in assembly of the ribonucleoprotein complex that includes the scaffold protein, Symplekin, and the cleavage and Polyadenylation specificity factor. Sumoylation of Symplekin is required for Polyadenylation, and both cleavage and Polyadenylation specificity factor and poly(A) polymerase are sumoylated. The foreshortened poly(A) tail is maintained by poly(A) ribonuclease, which associates with CPEB. While zinc-binding domains are renowned for nucleic acid recognition, binuclear zinc-binding structural motifs, such as LIM (Lin-11, Isl-1, Mec-3), RING (really interesting new gene), PHD (plant homeodomain) and ZZ (ZZ-type zinc finger) domains, participate in protein-protein interactions. Here, we report the solution structure of the C-terminal zinc-binding domain of CPEB1 (CPEB1-ZZ), which has a cross-braced zinc binding topology. The structural similarity to other ZZ domains suggests that the CPEB1-ZZ domain recruits sumoylated proteins during assembly of the ribonucleoprotein complex prior to mRNA export from the nucleus.
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Solution Structure of the Binuclear Zinc Finger of Cytoplasmic Polyadenylation Element Binding Protein (CPEB)
Biophysical Journal, 2012Co-Authors: Brian M. Lee, Daniel Merkel, Bryce Hilburn, Sarah WellsAbstract:Synaptic plasticity, the experience dependent variation in the strength of a synapse, is a means of encoding memory through a network of specific connections between neurons. Cytoplasmic Polyadenylation Element binding protein (CPEB) is a key factor in establishing the synaptic mark through translational regulation of protein synthesis. A neuronal isoform (CPEB1) participates in sequence specific recognition of a uracil-rich Cytoplasmic Polyadenylation Element (CPE) within the 3’ UTR of mRNA. The C-terminal region of CPEB1 binds to mRNA utilizing three structured domains including two RNA recognition motifs and a zinc finger domain. We have characterized the structure of the binuclear zinc finger domain by NMR spectroscopy.
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Structural Analysis of the C-Terminal RNA Binding Domain of CPEB3
Biophysical Journal, 2011Co-Authors: Bryce Hilburn, Daniel Merkel, Sarah Wells, Brian M. LeeAbstract:Cytoplasmic Polyadenylation Element binding protein isoform 3 (CPEB3) is a translational regulatory protein. There are four isoforms of CPEB. CPEB1 binds to a uracil rich Cytoplasmic Polyadenylation Element (CPE) sequence in the 3’UTR of mRNA and upon phosphorylation switches from an inhibitor to an activator of translation through regulation of Polyadenylation. CPEB3 does not promote Polyadenylation nor does it bind to the CPE sequence. Rather, CPEB3 recognizes a structured RNA motif in the 3’UTR and inhibits translation. CPEB comprises an N-terminal kinase-binding region, two RNA recognition motifs that function in molecular recognition and a C-terminal zinc finger that doe not influence specificity, but is required for binding RNA. Our initial research is focused on the recognition of a structured mRNA by CPEB3 for comparison with parallel studies of CPEB1 bound to a single stranded CPE sequence. We have cloned, expressed and purified the isotope labeled RNA binding region of CPEB3. Preliminary structural studies and assays of the RNA binding activity are presented.
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Structural Characterization of the Zinc Finger Domain of Cytoplasmic Polyadenylation Element-Binding Protein
Biophysical Journal, 2011Co-Authors: Daniel Merkel, Bryce Hilburn, Sarah Wells, Stephanie Geiser, Haley Hoover, Oluwatobi Ajoku, Brian M. LeeAbstract:Cytoplasmic Polyadenylation Element-binding protein (CPEB) is an important factor in translational regulation of oogenesis, cellular senescence and synaptic plasticity. It does this by regulating a poly(A) tail elongation through interactions with a number of other proteins. The region of mRNA that CPEB binds to is a uracil rich region known as the Cytoplasmic Polyadenylation Element (CPE). The carboxy terminal region of CPEB is composed of three regions that are required for CPE recognition and binding within the 3’ UTR of mRNA. It has two RNA binding domains and a zinc finger motif. The zinc finger region contains six cysteine and two histidine amino acids that are highly conserved throughout many species. The conserved residues suggest the presence of a zinc finger structure containing two zinc ions. The zinc finger region of CPEB does not seem to be homologous with any know zinc fingers. We are currently in the process of structural characterization using NMR techniques.
Sarah Wells - One of the best experts on this subject based on the ideXlab platform.
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the c terminal region of Cytoplasmic Polyadenylation Element binding protein is a zz domain with potential for protein protein interactions
Journal of Molecular Biology, 2013Co-Authors: Daniel Merkel, Bryce Hilburn, Sarah Wells, Fatima Elazzouzi, Gabriela C Perezalvarado, Brian M. LeeAbstract:Cytoplasmic Polyadenylation Element binding protein (CPEB) provides temporal and spatial control of protein synthesis required for early development and neuronal synaptic plasticity. CPEB regulates protein expression by inhibiting Polyadenylation of selected mRNA transcripts, which prevents binding of the ribosome for protein synthesis. Two RNA recognition motif domains and a C-terminal binuclear zinc-binding domain are required for mRNA binding, but the zinc-binding domain is not required for sequence-specific recognition of the targeted mRNA transcript. The structure and function of the zinc-binding domain of CPEB are unknown. The C-terminal region of CPEB may participate in assembly of the ribonucleoprotein complex that includes the scaffold protein, Symplekin, and the cleavage and Polyadenylation specificity factor. Sumoylation of Symplekin is required for Polyadenylation, and both cleavage and Polyadenylation specificity factor and poly(A) polymerase are sumoylated. The foreshortened poly(A) tail is maintained by poly(A) ribonuclease, which associates with CPEB. While zinc-binding domains are renowned for nucleic acid recognition, binuclear zinc-binding structural motifs, such as LIM (Lin-11, Isl-1, Mec-3), RING (really interesting new gene), PHD (plant homeodomain) and ZZ (ZZ-type zinc finger) domains, participate in protein-protein interactions. Here, we report the solution structure of the C-terminal zinc-binding domain of CPEB1 (CPEB1-ZZ), which has a cross-braced zinc binding topology. The structural similarity to other ZZ domains suggests that the CPEB1-ZZ domain recruits sumoylated proteins during assembly of the ribonucleoprotein complex prior to mRNA export from the nucleus.
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The C-Terminal Region of Cytoplasmic Polyadenylation Element Binding Protein Is a ZZ Domain with Potential for Protein–Protein Interactions
Journal of molecular biology, 2013Co-Authors: Daniel Merkel, Bryce Hilburn, Sarah Wells, Fatima Elazzouzi, Gabriela C. Pérez-alvarado, Brian M. LeeAbstract:Cytoplasmic Polyadenylation Element binding protein (CPEB) provides temporal and spatial control of protein synthesis required for early development and neuronal synaptic plasticity. CPEB regulates protein expression by inhibiting Polyadenylation of selected mRNA transcripts, which prevents binding of the ribosome for protein synthesis. Two RNA recognition motif domains and a C-terminal binuclear zinc-binding domain are required for mRNA binding, but the zinc-binding domain is not required for sequence-specific recognition of the targeted mRNA transcript. The structure and function of the zinc-binding domain of CPEB are unknown. The C-terminal region of CPEB may participate in assembly of the ribonucleoprotein complex that includes the scaffold protein, Symplekin, and the cleavage and Polyadenylation specificity factor. Sumoylation of Symplekin is required for Polyadenylation, and both cleavage and Polyadenylation specificity factor and poly(A) polymerase are sumoylated. The foreshortened poly(A) tail is maintained by poly(A) ribonuclease, which associates with CPEB. While zinc-binding domains are renowned for nucleic acid recognition, binuclear zinc-binding structural motifs, such as LIM (Lin-11, Isl-1, Mec-3), RING (really interesting new gene), PHD (plant homeodomain) and ZZ (ZZ-type zinc finger) domains, participate in protein-protein interactions. Here, we report the solution structure of the C-terminal zinc-binding domain of CPEB1 (CPEB1-ZZ), which has a cross-braced zinc binding topology. The structural similarity to other ZZ domains suggests that the CPEB1-ZZ domain recruits sumoylated proteins during assembly of the ribonucleoprotein complex prior to mRNA export from the nucleus.
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Solution Structure of the Binuclear Zinc Finger of Cytoplasmic Polyadenylation Element Binding Protein (CPEB)
Biophysical Journal, 2012Co-Authors: Brian M. Lee, Daniel Merkel, Bryce Hilburn, Sarah WellsAbstract:Synaptic plasticity, the experience dependent variation in the strength of a synapse, is a means of encoding memory through a network of specific connections between neurons. Cytoplasmic Polyadenylation Element binding protein (CPEB) is a key factor in establishing the synaptic mark through translational regulation of protein synthesis. A neuronal isoform (CPEB1) participates in sequence specific recognition of a uracil-rich Cytoplasmic Polyadenylation Element (CPE) within the 3’ UTR of mRNA. The C-terminal region of CPEB1 binds to mRNA utilizing three structured domains including two RNA recognition motifs and a zinc finger domain. We have characterized the structure of the binuclear zinc finger domain by NMR spectroscopy.
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Structural Analysis of the C-Terminal RNA Binding Domain of CPEB3
Biophysical Journal, 2011Co-Authors: Bryce Hilburn, Daniel Merkel, Sarah Wells, Brian M. LeeAbstract:Cytoplasmic Polyadenylation Element binding protein isoform 3 (CPEB3) is a translational regulatory protein. There are four isoforms of CPEB. CPEB1 binds to a uracil rich Cytoplasmic Polyadenylation Element (CPE) sequence in the 3’UTR of mRNA and upon phosphorylation switches from an inhibitor to an activator of translation through regulation of Polyadenylation. CPEB3 does not promote Polyadenylation nor does it bind to the CPE sequence. Rather, CPEB3 recognizes a structured RNA motif in the 3’UTR and inhibits translation. CPEB comprises an N-terminal kinase-binding region, two RNA recognition motifs that function in molecular recognition and a C-terminal zinc finger that doe not influence specificity, but is required for binding RNA. Our initial research is focused on the recognition of a structured mRNA by CPEB3 for comparison with parallel studies of CPEB1 bound to a single stranded CPE sequence. We have cloned, expressed and purified the isotope labeled RNA binding region of CPEB3. Preliminary structural studies and assays of the RNA binding activity are presented.
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Structural Characterization of the Zinc Finger Domain of Cytoplasmic Polyadenylation Element-Binding Protein
Biophysical Journal, 2011Co-Authors: Daniel Merkel, Bryce Hilburn, Sarah Wells, Stephanie Geiser, Haley Hoover, Oluwatobi Ajoku, Brian M. LeeAbstract:Cytoplasmic Polyadenylation Element-binding protein (CPEB) is an important factor in translational regulation of oogenesis, cellular senescence and synaptic plasticity. It does this by regulating a poly(A) tail elongation through interactions with a number of other proteins. The region of mRNA that CPEB binds to is a uracil rich region known as the Cytoplasmic Polyadenylation Element (CPE). The carboxy terminal region of CPEB is composed of three regions that are required for CPE recognition and binding within the 3’ UTR of mRNA. It has two RNA binding domains and a zinc finger motif. The zinc finger region contains six cysteine and two histidine amino acids that are highly conserved throughout many species. The conserved residues suggest the presence of a zinc finger structure containing two zinc ions. The zinc finger region of CPEB does not seem to be homologous with any know zinc fingers. We are currently in the process of structural characterization using NMR techniques.
Bryce Hilburn - One of the best experts on this subject based on the ideXlab platform.
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the c terminal region of Cytoplasmic Polyadenylation Element binding protein is a zz domain with potential for protein protein interactions
Journal of Molecular Biology, 2013Co-Authors: Daniel Merkel, Bryce Hilburn, Sarah Wells, Fatima Elazzouzi, Gabriela C Perezalvarado, Brian M. LeeAbstract:Cytoplasmic Polyadenylation Element binding protein (CPEB) provides temporal and spatial control of protein synthesis required for early development and neuronal synaptic plasticity. CPEB regulates protein expression by inhibiting Polyadenylation of selected mRNA transcripts, which prevents binding of the ribosome for protein synthesis. Two RNA recognition motif domains and a C-terminal binuclear zinc-binding domain are required for mRNA binding, but the zinc-binding domain is not required for sequence-specific recognition of the targeted mRNA transcript. The structure and function of the zinc-binding domain of CPEB are unknown. The C-terminal region of CPEB may participate in assembly of the ribonucleoprotein complex that includes the scaffold protein, Symplekin, and the cleavage and Polyadenylation specificity factor. Sumoylation of Symplekin is required for Polyadenylation, and both cleavage and Polyadenylation specificity factor and poly(A) polymerase are sumoylated. The foreshortened poly(A) tail is maintained by poly(A) ribonuclease, which associates with CPEB. While zinc-binding domains are renowned for nucleic acid recognition, binuclear zinc-binding structural motifs, such as LIM (Lin-11, Isl-1, Mec-3), RING (really interesting new gene), PHD (plant homeodomain) and ZZ (ZZ-type zinc finger) domains, participate in protein-protein interactions. Here, we report the solution structure of the C-terminal zinc-binding domain of CPEB1 (CPEB1-ZZ), which has a cross-braced zinc binding topology. The structural similarity to other ZZ domains suggests that the CPEB1-ZZ domain recruits sumoylated proteins during assembly of the ribonucleoprotein complex prior to mRNA export from the nucleus.
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The C-Terminal Region of Cytoplasmic Polyadenylation Element Binding Protein Is a ZZ Domain with Potential for Protein–Protein Interactions
Journal of molecular biology, 2013Co-Authors: Daniel Merkel, Bryce Hilburn, Sarah Wells, Fatima Elazzouzi, Gabriela C. Pérez-alvarado, Brian M. LeeAbstract:Cytoplasmic Polyadenylation Element binding protein (CPEB) provides temporal and spatial control of protein synthesis required for early development and neuronal synaptic plasticity. CPEB regulates protein expression by inhibiting Polyadenylation of selected mRNA transcripts, which prevents binding of the ribosome for protein synthesis. Two RNA recognition motif domains and a C-terminal binuclear zinc-binding domain are required for mRNA binding, but the zinc-binding domain is not required for sequence-specific recognition of the targeted mRNA transcript. The structure and function of the zinc-binding domain of CPEB are unknown. The C-terminal region of CPEB may participate in assembly of the ribonucleoprotein complex that includes the scaffold protein, Symplekin, and the cleavage and Polyadenylation specificity factor. Sumoylation of Symplekin is required for Polyadenylation, and both cleavage and Polyadenylation specificity factor and poly(A) polymerase are sumoylated. The foreshortened poly(A) tail is maintained by poly(A) ribonuclease, which associates with CPEB. While zinc-binding domains are renowned for nucleic acid recognition, binuclear zinc-binding structural motifs, such as LIM (Lin-11, Isl-1, Mec-3), RING (really interesting new gene), PHD (plant homeodomain) and ZZ (ZZ-type zinc finger) domains, participate in protein-protein interactions. Here, we report the solution structure of the C-terminal zinc-binding domain of CPEB1 (CPEB1-ZZ), which has a cross-braced zinc binding topology. The structural similarity to other ZZ domains suggests that the CPEB1-ZZ domain recruits sumoylated proteins during assembly of the ribonucleoprotein complex prior to mRNA export from the nucleus.
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Solution Structure of the Binuclear Zinc Finger of Cytoplasmic Polyadenylation Element Binding Protein (CPEB)
Biophysical Journal, 2012Co-Authors: Brian M. Lee, Daniel Merkel, Bryce Hilburn, Sarah WellsAbstract:Synaptic plasticity, the experience dependent variation in the strength of a synapse, is a means of encoding memory through a network of specific connections between neurons. Cytoplasmic Polyadenylation Element binding protein (CPEB) is a key factor in establishing the synaptic mark through translational regulation of protein synthesis. A neuronal isoform (CPEB1) participates in sequence specific recognition of a uracil-rich Cytoplasmic Polyadenylation Element (CPE) within the 3’ UTR of mRNA. The C-terminal region of CPEB1 binds to mRNA utilizing three structured domains including two RNA recognition motifs and a zinc finger domain. We have characterized the structure of the binuclear zinc finger domain by NMR spectroscopy.
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Structural Analysis of the C-Terminal RNA Binding Domain of CPEB3
Biophysical Journal, 2011Co-Authors: Bryce Hilburn, Daniel Merkel, Sarah Wells, Brian M. LeeAbstract:Cytoplasmic Polyadenylation Element binding protein isoform 3 (CPEB3) is a translational regulatory protein. There are four isoforms of CPEB. CPEB1 binds to a uracil rich Cytoplasmic Polyadenylation Element (CPE) sequence in the 3’UTR of mRNA and upon phosphorylation switches from an inhibitor to an activator of translation through regulation of Polyadenylation. CPEB3 does not promote Polyadenylation nor does it bind to the CPE sequence. Rather, CPEB3 recognizes a structured RNA motif in the 3’UTR and inhibits translation. CPEB comprises an N-terminal kinase-binding region, two RNA recognition motifs that function in molecular recognition and a C-terminal zinc finger that doe not influence specificity, but is required for binding RNA. Our initial research is focused on the recognition of a structured mRNA by CPEB3 for comparison with parallel studies of CPEB1 bound to a single stranded CPE sequence. We have cloned, expressed and purified the isotope labeled RNA binding region of CPEB3. Preliminary structural studies and assays of the RNA binding activity are presented.
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Structural Characterization of the Zinc Finger Domain of Cytoplasmic Polyadenylation Element-Binding Protein
Biophysical Journal, 2011Co-Authors: Daniel Merkel, Bryce Hilburn, Sarah Wells, Stephanie Geiser, Haley Hoover, Oluwatobi Ajoku, Brian M. LeeAbstract:Cytoplasmic Polyadenylation Element-binding protein (CPEB) is an important factor in translational regulation of oogenesis, cellular senescence and synaptic plasticity. It does this by regulating a poly(A) tail elongation through interactions with a number of other proteins. The region of mRNA that CPEB binds to is a uracil rich region known as the Cytoplasmic Polyadenylation Element (CPE). The carboxy terminal region of CPEB is composed of three regions that are required for CPE recognition and binding within the 3’ UTR of mRNA. It has two RNA binding domains and a zinc finger motif. The zinc finger region contains six cysteine and two histidine amino acids that are highly conserved throughout many species. The conserved residues suggest the presence of a zinc finger structure containing two zinc ions. The zinc finger region of CPEB does not seem to be homologous with any know zinc fingers. We are currently in the process of structural characterization using NMR techniques.
