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Eva-maria Mandelkow - One of the best experts on this subject based on the ideXlab platform.
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Phosphorylation of Human Tau Protein by Microtubule Affinity-Regulating Kinase 2
Biochemistry, 2013Co-Authors: Martin Schwalbe, Eva-maria Mandelkow, Jacek Biernat, Stefan Bibow, Valéry Ozenne, Malene Ringkjøbing Jensen, Harindranath Kadavath, Martin Blackledge, Markus ZweckstetterAbstract:Tau protein plays an important role in neuronal physiology and Alzheimer's neurodegeneration. Its abilities to aggregate abnormally, to bind to microtubules (MTs), and to promote MT assembly are all influenced by phosphorylation. Phosphorylation of serine residues in the KXGS motifs of Tau's repeat domain, crucial for MT interactions and aggregation, is facilitated most efficiently by microtubule-associated protein/microtubule affinity-regulating kinases (MARKs). Here we applied high-resolution nuclear magnetic resonance analysis to study the kinetics of phosphorylation of Tau by MARK2 and its impact on the structure and microtubule binding of Tau. We demonstrate that MARK2 binds to the N-terminal tail of Tau and selectively phosphorylates three major and five minor serine residues in the repeat domain and C-terminal tail. Structural changes induced by phosphorylation of Tau by MARK2 are highly localized in the proximity of the phosphorylation site and do not affect the global conformation, in contrast to phosphorylation in the proline-rich region. Furthermore, single-residue analysis of binding of Tau to MTs provides support for a model in which Tau's hot spots of MT interaction bind independently of each other and are differentially affected by phosphorylation.
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microtubule affinity regulating kinase 2 MARK2 turns on phosphatase and tensin homolog pten induced kinase 1 pink1 at thr 313 a mutation site in parkinson disease effects on mitochondrial transport
Journal of Biological Chemistry, 2012Co-Authors: Dorthe Matenia, Cindy Hempp, Annika Eikhof, Thomas Timm, Eva-maria MandelkowAbstract:The kinase MARK2/Par-1 plays key roles in several cell processes, including neurodegeneration such as Alzheimer disease by phosphorylating tau and detaching it from microtubules. In search of interaction partners of MARK2, we identified phosphatase and tensin homolog (PTEN)-induced kinase 1 (PINK1), which is important for the survival of neurons and whose mutations are linked to familial Parkinson disease (PD). MARK2 phosphorylated and activated the cleaved form of PINK1 (ΔN-PINK1; amino acids 156–581). Thr-313 was the primary phosphorylation site, a residue mutated to a non-phosphorylatable form (T313M) in a frequent variant of PD. Mutation of Thr-313 to Met or Glu in PINK1 showed toxic effects with abnormal mitochondrial distribution in neurons. MARK2 and PINK1 were found to colocalize with mitochondria and regulate their transport. ΔN-PINK1 promoted anterograde transport and increased the fraction of stationary mitochondria, whereas full-length PINK1 promoted retrograde transport. In both cases, MARK2 enhanced the effects. The results identify MARK2 as an upstream regulator of PINK1 and ΔN-PINK1 and provide insights into the regulation of mitochondrial trafficking in neurons and neurodegeneration in PD.
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Antagonistic Effects of Doublecortin and MARK2/Par-1 in the Developing Cerebral Cortex
The Journal of neuroscience : the official journal of the Society for Neuroscience, 2008Co-Authors: Tamar Sapir, Thomas Timm, Eva-maria Mandelkow, Talia Levy, Anat Shmueli, Michael Elbaum, Orly ReinerAbstract:Abnormal neuronal migration is manifested in brain malformations such as lissencephaly. The impairment in coordinated cell motility likely reflects a faulty mechanism of cell polarization or coupling between polarization and movement. Here we report on the relationship between the polarity kinase MARK2/Par-1 and its substrate, the well-known lissencephaly-associated gene doublecortin (DCX), during cortical radial migration. We have previously shown using in utero electroporation that reduced MARK2 levels resulted in multipolar neurons stalled at the intermediate zone border, similar to the phenotype observed in the case of DCX silencing. However, whereas reduced MARK2 stabilized microtubules, we show here that knock-down of DCX increased microtubule dynamics. This led to the hypothesis that simultaneous reduction may alleviate the phenotype. Coreduction of MARK2 and DCX resulted in a partial restoration of the normal neuronal migration phenotype in vivo. The kinetic behavior of the centrosomes reflected the different molecular mechanisms activated when either protein was reduced. In the case of reducing MARK2 processive motility of the centrosome was hindered, whereas when DCX was reduced, centrosomes moved quickly but bidirectionally. Our results stress the necessity for successful coupling between the polarity pathway and cytoplasmic dynein-dependent activities for proper neuronal migration.
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antagonistic effects of doublecortin and MARK2 par 1 in the developing cerebral cortex
The Journal of Neuroscience, 2008Co-Authors: Tamar Sapir, Thomas Timm, Eva-maria Mandelkow, Talia Levy, Anat Shmueli, Michael Elbaum, Orly ReinerAbstract:Abnormal neuronal migration is manifested in brain malformations such as lissencephaly. The impairment in coordinated cell motility likely reflects a faulty mechanism of cell polarization or coupling between polarization and movement. Here we report on the relationship between the polarity kinase MARK2/Par-1 and its substrate, the well-known lissencephaly-associated gene doublecortin (DCX), during cortical radial migration. We have previously shown using in utero electroporation that reduced MARK2 levels resulted in multipolar neurons stalled at the intermediate zone border, similar to the phenotype observed in the case of DCX silencing. However, whereas reduced MARK2 stabilized microtubules, we show here that knock-down of DCX increased microtubule dynamics. This led to the hypothesis that simultaneous reduction may alleviate the phenotype. Coreduction of MARK2 and DCX resulted in a partial restoration of the normal neuronal migration phenotype in vivo. The kinetic behavior of the centrosomes reflected the different molecular mechanisms activated when either protein was reduced. In the case of reducing MARK2 processive motility of the centrosome was hindered, whereas when DCX was reduced, centrosomes moved quickly but bidirectionally. Our results stress the necessity for successful coupling between the polarity pathway and cytoplasmic dynein-dependent activities for proper neuronal migration.
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Accurate Balance of the Polarity Kinase MARK2/Par-1 Is Required for Proper Cortical Neuronal Migration
The Journal of neuroscience : the official journal of the Society for Neuroscience, 2008Co-Authors: Tamar Sapir, Thomas Timm, Eva-maria Mandelkow, Sivan Sapoznik, Talia Levy, Danit Finkelshtein, Anat Shmueli, Orly ReinerAbstract:Radial neuronal migration is key in structuring the layered cortex. Here we studied the role of MARK2/Par-1 in this process. The dual name stands for the MAP/microtubule affinity-regulating kinase 2 (MARK2) and the known polarity kinase 1 (Par-1). Reduced MARK2 levels using in utero electroporation resulted in multipolar neurons stalled at the intermediate zone border. Reintroduction of the wild-type kinase postmitotically improved neuronal migration. Our results indicated that reduction in MARK2 affected centrosomal dynamics in migrating neurons of the cerebral cortex. Increased MARK2 has been shown to destabilize microtubules, and here we show for the first time that reduced MARK2 stabilized microtubules in primary cultured neurons. Kinase-independent activity permitted multipolar-to-bipolar transition but did not restore proper migration. Increased MARK2 levels resulted in a different phenotype, which is loss of neuronal polarity. MARK2 kinase activity reduction hindered migration in the developing brain, which was rescued by increasing kinase activity. Our results stress the necessity of maintaining dynamic microtubules for proper neuronal migration. Furthermore, the exact requirements for MARK2 and its kinase activity vary during the course of neuronal migration. Collectively, our results stress the requirements for the different roles of MARK2 during neuronal migration.
Thomas Timm - One of the best experts on this subject based on the ideXlab platform.
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microtubule affinity regulating kinase 2 MARK2 turns on phosphatase and tensin homolog pten induced kinase 1 pink1 at thr 313 a mutation site in parkinson disease effects on mitochondrial transport
Journal of Biological Chemistry, 2012Co-Authors: Dorthe Matenia, Cindy Hempp, Annika Eikhof, Thomas Timm, Eva-maria MandelkowAbstract:The kinase MARK2/Par-1 plays key roles in several cell processes, including neurodegeneration such as Alzheimer disease by phosphorylating tau and detaching it from microtubules. In search of interaction partners of MARK2, we identified phosphatase and tensin homolog (PTEN)-induced kinase 1 (PINK1), which is important for the survival of neurons and whose mutations are linked to familial Parkinson disease (PD). MARK2 phosphorylated and activated the cleaved form of PINK1 (ΔN-PINK1; amino acids 156–581). Thr-313 was the primary phosphorylation site, a residue mutated to a non-phosphorylatable form (T313M) in a frequent variant of PD. Mutation of Thr-313 to Met or Glu in PINK1 showed toxic effects with abnormal mitochondrial distribution in neurons. MARK2 and PINK1 were found to colocalize with mitochondria and regulate their transport. ΔN-PINK1 promoted anterograde transport and increased the fraction of stationary mitochondria, whereas full-length PINK1 promoted retrograde transport. In both cases, MARK2 enhanced the effects. The results identify MARK2 as an upstream regulator of PINK1 and ΔN-PINK1 and provide insights into the regulation of mitochondrial trafficking in neurons and neurodegeneration in PD.
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Antagonistic Effects of Doublecortin and MARK2/Par-1 in the Developing Cerebral Cortex
The Journal of neuroscience : the official journal of the Society for Neuroscience, 2008Co-Authors: Tamar Sapir, Thomas Timm, Eva-maria Mandelkow, Talia Levy, Anat Shmueli, Michael Elbaum, Orly ReinerAbstract:Abnormal neuronal migration is manifested in brain malformations such as lissencephaly. The impairment in coordinated cell motility likely reflects a faulty mechanism of cell polarization or coupling between polarization and movement. Here we report on the relationship between the polarity kinase MARK2/Par-1 and its substrate, the well-known lissencephaly-associated gene doublecortin (DCX), during cortical radial migration. We have previously shown using in utero electroporation that reduced MARK2 levels resulted in multipolar neurons stalled at the intermediate zone border, similar to the phenotype observed in the case of DCX silencing. However, whereas reduced MARK2 stabilized microtubules, we show here that knock-down of DCX increased microtubule dynamics. This led to the hypothesis that simultaneous reduction may alleviate the phenotype. Coreduction of MARK2 and DCX resulted in a partial restoration of the normal neuronal migration phenotype in vivo. The kinetic behavior of the centrosomes reflected the different molecular mechanisms activated when either protein was reduced. In the case of reducing MARK2 processive motility of the centrosome was hindered, whereas when DCX was reduced, centrosomes moved quickly but bidirectionally. Our results stress the necessity for successful coupling between the polarity pathway and cytoplasmic dynein-dependent activities for proper neuronal migration.
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antagonistic effects of doublecortin and MARK2 par 1 in the developing cerebral cortex
The Journal of Neuroscience, 2008Co-Authors: Tamar Sapir, Thomas Timm, Eva-maria Mandelkow, Talia Levy, Anat Shmueli, Michael Elbaum, Orly ReinerAbstract:Abnormal neuronal migration is manifested in brain malformations such as lissencephaly. The impairment in coordinated cell motility likely reflects a faulty mechanism of cell polarization or coupling between polarization and movement. Here we report on the relationship between the polarity kinase MARK2/Par-1 and its substrate, the well-known lissencephaly-associated gene doublecortin (DCX), during cortical radial migration. We have previously shown using in utero electroporation that reduced MARK2 levels resulted in multipolar neurons stalled at the intermediate zone border, similar to the phenotype observed in the case of DCX silencing. However, whereas reduced MARK2 stabilized microtubules, we show here that knock-down of DCX increased microtubule dynamics. This led to the hypothesis that simultaneous reduction may alleviate the phenotype. Coreduction of MARK2 and DCX resulted in a partial restoration of the normal neuronal migration phenotype in vivo. The kinetic behavior of the centrosomes reflected the different molecular mechanisms activated when either protein was reduced. In the case of reducing MARK2 processive motility of the centrosome was hindered, whereas when DCX was reduced, centrosomes moved quickly but bidirectionally. Our results stress the necessity for successful coupling between the polarity pathway and cytoplasmic dynein-dependent activities for proper neuronal migration.
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Accurate Balance of the Polarity Kinase MARK2/Par-1 Is Required for Proper Cortical Neuronal Migration
The Journal of neuroscience : the official journal of the Society for Neuroscience, 2008Co-Authors: Tamar Sapir, Thomas Timm, Eva-maria Mandelkow, Sivan Sapoznik, Talia Levy, Danit Finkelshtein, Anat Shmueli, Orly ReinerAbstract:Radial neuronal migration is key in structuring the layered cortex. Here we studied the role of MARK2/Par-1 in this process. The dual name stands for the MAP/microtubule affinity-regulating kinase 2 (MARK2) and the known polarity kinase 1 (Par-1). Reduced MARK2 levels using in utero electroporation resulted in multipolar neurons stalled at the intermediate zone border. Reintroduction of the wild-type kinase postmitotically improved neuronal migration. Our results indicated that reduction in MARK2 affected centrosomal dynamics in migrating neurons of the cerebral cortex. Increased MARK2 has been shown to destabilize microtubules, and here we show for the first time that reduced MARK2 stabilized microtubules in primary cultured neurons. Kinase-independent activity permitted multipolar-to-bipolar transition but did not restore proper migration. Increased MARK2 levels resulted in a different phenotype, which is loss of neuronal polarity. MARK2 kinase activity reduction hindered migration in the developing brain, which was rescued by increasing kinase activity. Our results stress the necessity of maintaining dynamic microtubules for proper neuronal migration. Furthermore, the exact requirements for MARK2 and its kinase activity vary during the course of neuronal migration. Collectively, our results stress the requirements for the different roles of MARK2 during neuronal migration.
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accurate balance of the polarity kinase MARK2 par 1 is required for proper cortical neuronal migration
The Journal of Neuroscience, 2008Co-Authors: Tamar Sapir, Thomas Timm, Eva-maria Mandelkow, Sivan Sapoznik, Talia Levy, Danit Finkelshtein, Anat Shmueli, Orly ReinerAbstract:Radial neuronal migration is key in structuring the layered cortex. Here we studied the role of MARK2/Par-1 in this process. The dual name stands for the MAP/microtubule affinity-regulating kinase 2 (MARK2) and the known polarity kinase 1 (Par-1). Reduced MARK2 levels using in utero electroporation resulted in multipolar neurons stalled at the intermediate zone border. Reintroduction of the wild-type kinase postmitotically improved neuronal migration. Our results indicated that reduction in MARK2 affected centrosomal dynamics in migrating neurons of the cerebral cortex. Increased MARK2 has been shown to destabilize microtubules, and here we show for the first time that reduced MARK2 stabilized microtubules in primary cultured neurons. Kinase-independent activity permitted multipolar-to-bipolar transition but did not restore proper migration. Increased MARK2 levels resulted in a different phenotype, which is loss of neuronal polarity. MARK2 kinase activity reduction hindered migration in the developing brain, which was rescued by increasing kinase activity. Our results stress the necessity of maintaining dynamic microtubules for proper neuronal migration. Furthermore, the exact requirements for MARK2 and its kinase activity vary during the course of neuronal migration. Collectively, our results stress the requirements for the different roles of MARK2 during neuronal migration.
Nobutaka Hirokawa - One of the best experts on this subject based on the ideXlab platform.
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the spatiotemporal construction of the axon initial segment via kif3 kap3 trim46 transport under MARK2 signaling
Cell Reports, 2019Co-Authors: Sotaro Ichinose, Nobutaka Hirokawa, Tadayuki Ogawa, Xuguang JiangAbstract:Summary The axon initial segment (AIS) is a compartment that serves as a molecular barrier to achieve axon-dendrite differentiation. Distribution of specific proteins during early neuronal development has been proposed to be critical for AIS construction. However, it remains unknown how these proteins are specifically targeted to the proximal axon within this limited time period. Here, we reveal spatiotemporal regulation driven by the microtubule (MT)-based motor KIF3A/B/KAP3 that transports TRIM46, influenced by a specific MARK2 phosphorylation cascade. In the proximal part of the future axon under low MARK2 activity, the KIF3/KAP3 motor recognizes TRIM46 as cargo and transports it to the future AIS. In contrast, in the somatodendritic area under high MARK2 activity, KAP3 phosphorylated at serine 60 by MARK2 cannot bind with TRIM46 and be transported. This spatiotemporal regulation between KIF3/KAP3 and TRIM46 under specific MARK2 activity underlies the specific transport needed for axonal differentiation.
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The Spatiotemporal Construction of the Axon Initial Segment via KIF3/KAP3/TRIM46 Transport under MARK2 Signaling.
Cell reports, 2019Co-Authors: Sotaro Ichinose, Tadayuki Ogawa, Xuguang Jiang, Nobutaka HirokawaAbstract:Summary The axon initial segment (AIS) is a compartment that serves as a molecular barrier to achieve axon-dendrite differentiation. Distribution of specific proteins during early neuronal development has been proposed to be critical for AIS construction. However, it remains unknown how these proteins are specifically targeted to the proximal axon within this limited time period. Here, we reveal spatiotemporal regulation driven by the microtubule (MT)-based motor KIF3A/B/KAP3 that transports TRIM46, influenced by a specific MARK2 phosphorylation cascade. In the proximal part of the future axon under low MARK2 activity, the KIF3/KAP3 motor recognizes TRIM46 as cargo and transports it to the future AIS. In contrast, in the somatodendritic area under high MARK2 activity, KAP3 phosphorylated at serine 60 by MARK2 cannot bind with TRIM46 and be transported. This spatiotemporal regulation between KIF3/KAP3 and TRIM46 under specific MARK2 activity underlies the specific transport needed for axonal differentiation.
Viji M. Draviam - One of the best experts on this subject based on the ideXlab platform.
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MARK2 par1b kinase present at centrosomes and retraction fibres corrects spindle off centring induced by actin disassembly
Open Biology, 2019Co-Authors: Madeleine Hart, Ihsan N. Zulkipli, Roshan L. Shrestha, Duccio Conti, Izabela Kujawiak, David Dang, Parveen Gul, Viji M. DraviamAbstract:Tissue maintenance and development requires a directed plane of cell division. While it is clear that the division plane can be determined by retraction fibres that guide spindle movements, the precise molecular components of retraction fibres that control spindle movements remain unclear. We report MARK2/Par1b kinase as a novel component of actin-rich retraction fibres. A kinase-dead mutant of MARK2 reveals MARK2's ability to monitor subcellular actin status during interphase. During mitosis, MARK2's localization at actin-rich retraction fibres, but not the rest of the cortical membrane or centrosome, is dependent on its activity, highlighting a specialized spatial regulation of MARK2. By subtly perturbing the actin cytoskeleton, we reveal MARK2's role in correcting mitotic spindle off-centring induced by actin disassembly. We propose that MARK2 provides a molecular framework to integrate cortical signals and cytoskeletal changes in mitosis and interphase.
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MARK2/Par1b present at retraction fibres corrects spindle off-centering induced by actin disassembly
2018Co-Authors: Madeleine Hart, Ihsan N. Zulkipli, Roshan L. Shrestha, Duccio Conti, Izabela Kujawiak, Viji M. DraviamAbstract:Abstract Tissue maintenance requires adequate cell proliferation and a directed plane of cell division. Retraction fibres can determine the plane of cell division by directing spindle movements; however, retraction fibre components that direct spindle movements remain unclear. We report MARK2/Par1b kinase as a novel component of actin-rich retraction fibres, important for directed spindle movements. A kinase-dead mutant of MARK2 reveals MARK2’s ability to monitor actin status. MARK2’s localisation at retraction fibres, but not the rest of the cortical membrane or centrosome, is dependent on its kinase activity, highlighting a specialised spatial regulation of MARK2. By subtly perturbing the actin cytoskeleton, we demonstrate MARK2’s role in correcting spindle off-centering, induced by lesions in actin assembly. In addition to this mitotic role, we show MARK2’s post-mitotic role in ensuring normal G1-S progression and cell proliferation. We propose that MARK2 provides a molecular framework to integrate cortical signals and cytoskeletal changes in both mitosis and interphase. Short Summary Coordination of cell proliferation and division is important for tissue maintenance. We report a regulated localisation for MARK2 in mitosis and interphase. We demonstrate its mitotic role in correcting spindle positioning defects and its interphase role in G1-S transition.
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MARK2 par1b present at retraction fibres corrects spindle off centering induced by actin disassembly
bioRxiv, 2018Co-Authors: Madeleine Hart, Ihsan N. Zulkipli, Roshan L. Shrestha, Duccio Conti, Izabela Kujawiak, Viji M. Draviam, D D DangAbstract:Abstract Tissue maintenance requires adequate cell proliferation and a directed plane of cell division. Retraction fibres can determine the plane of cell division by directing spindle movements; however, retraction fibre components that direct spindle movements remain unclear. We report MARK2/Par1b kinase as a novel component of actin-rich retraction fibres, important for directed spindle movements. A kinase-dead mutant of MARK2 reveals MARK2’s ability to monitor actin status. MARK2’s localisation at retraction fibres, but not the rest of the cortical membrane or centrosome, is dependent on its kinase activity, highlighting a specialised spatial regulation of MARK2. By subtly perturbing the actin cytoskeleton, we demonstrate MARK2’s role in correcting spindle off-centering, induced by lesions in actin assembly. In addition to this mitotic role, we show MARK2’s post-mitotic role in ensuring normal G1-S progression and cell proliferation. We propose that MARK2 provides a molecular framework to integrate cortical signals and cytoskeletal changes in both mitosis and interphase. Short Summary Coordination of cell proliferation and division is important for tissue maintenance. We report a regulated localisation for MARK2 in mitosis and interphase. We demonstrate its mitotic role in correcting spindle positioning defects and its interphase role in G1-S transition.
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Spindle rotation in human cells is reliant on a MARK2-mediated equatorial spindle-centering mechanism
Journal of Cell Biology, 2018Co-Authors: Ihsan N. Zulkipli, Madeleine Hart, Roshan L. Shrestha, Izabela Kujawiak, David Dang, Joanna Clark, Tami Kasichiwin, Nishanth Sastry, Viji M. DraviamAbstract:The plane of cell division is defined by the final position of the mitotic spindle. The spindle is pulled and rotated to the correct position by cortical dynein. However, it is unclear how the spindle’s rotational center is maintained and what the consequences of an equatorially off centered spindle are in human cells. We analyzed spindle movements in 100s of cells exposed to protein depletions or drug treatments and uncovered a novel role for MARK2 in maintaining the spindle at the cell’s geometric center. Following MARK2 depletion, spindles glide along the cell cortex, leading to a failure in identifying the correct division plane. Surprisingly, spindle off centering in MARK2-depleted cells is not caused by excessive pull by dynein. We show that MARK2 modulates mitotic microtubule growth and length and that codepleting mitotic centromere-associated protein (MCAK), a microtubule destabilizer, rescues spindle off centering in MARK2-depleted cells. Thus, we provide the first insight into a spindle-centering mechanism needed for proper spindle rotation and, in turn, the correct division plane in human cells.
Jacek Biernat - One of the best experts on this subject based on the ideXlab platform.
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Phosphorylation of Human Tau Protein by Microtubule Affinity-Regulating Kinase 2
Biochemistry, 2013Co-Authors: Martin Schwalbe, Eva-maria Mandelkow, Jacek Biernat, Stefan Bibow, Valéry Ozenne, Malene Ringkjøbing Jensen, Harindranath Kadavath, Martin Blackledge, Markus ZweckstetterAbstract:Tau protein plays an important role in neuronal physiology and Alzheimer's neurodegeneration. Its abilities to aggregate abnormally, to bind to microtubules (MTs), and to promote MT assembly are all influenced by phosphorylation. Phosphorylation of serine residues in the KXGS motifs of Tau's repeat domain, crucial for MT interactions and aggregation, is facilitated most efficiently by microtubule-associated protein/microtubule affinity-regulating kinases (MARKs). Here we applied high-resolution nuclear magnetic resonance analysis to study the kinetics of phosphorylation of Tau by MARK2 and its impact on the structure and microtubule binding of Tau. We demonstrate that MARK2 binds to the N-terminal tail of Tau and selectively phosphorylates three major and five minor serine residues in the repeat domain and C-terminal tail. Structural changes induced by phosphorylation of Tau by MARK2 are highly localized in the proximity of the phosphorylation site and do not affect the global conformation, in contrast to phosphorylation in the proline-rich region. Furthermore, single-residue analysis of binding of Tau to MTs provides support for a model in which Tau's hot spots of MT interaction bind independently of each other and are differentially affected by phosphorylation.
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Glycogen Synthase Kinase (GSK) 3β Directly Phosphorylates Serine 212 in the Regulatory Loop and Inhibits Microtubule Affinity-regulating Kinase (MARK) 2
The Journal of biological chemistry, 2008Co-Authors: Thomas Timm, Eva-maria Mandelkow, Jacek Biernat, Kiruthiga BalusamyAbstract:Abstract MARK/Par-1, a kinase family with diverse functions particularly in inducing cell polarity, can phosphorylate microtubule-associated proteins in their repeat domain and cause their detachment from microtubules, and thereby microtubule destabilization. Because of its role in abnormal phosphorylation of the Tau protein in Alzheimer disease, we searched for regulatory kinases. MARK family kinases can be activated by phosphorylation of a conserved threonine (Thr-208 in MARK2), and inactivated by phosphorylation of a serine (Ser-212), both in the activation loop of the catalytic domain. Activation is achieved by the kinases MARKK/TAO1 or LKB1, although the inactivating kinase was unknown. We show here that GSK3β serves the role of the inhibitory kinase. Because GSK3β can also phosphorylate Tau at sites outside the repeat domain, the activation of GSK3β, and concomitant inactivation of MARK can shift the pattern of pathological phosphorylation of Tau protein in Alzheimer disease.
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Glycogen Synthase Kinase (GSK) 3 Directly Phosphorylates Serine 212 in the Regulatory Loop and Inhibits Microtubule
2008Co-Authors: Thomas Timm, Eva-maria Mandelkow, Jacek Biernat, Kiruthiga BalusamyAbstract:MARK/Par-1, a kinase family with diverse functions particularly in inducing cell polarity, can phosphorylate microtubule-associated proteins in their repeat domain and cause their detachment from microtubules, and thereby microtubule destabilization. Because of its role in abnormal phosphorylation of the Tau protein in Alzheimer disease, we searched for regulatory kinases. MARK family kinases can be activated by phosphorylation of a conserved threonine (Thr-208 in MARK2), and inactivated by phosphorylation of a serine (Ser212), both in the activation loop of the catalytic domain. Activation is achieved by the kinases MARKK/TAO1 or LKB1, although the inactivating kinase was unknown. We show here that GSK3 serves the role of the inhibitory kinase. Because GSK3 can also phosphorylate Tau at sites outside the repeat domain, the activation of GSK3, and concomitant inactivation of MARK can shift the pattern of pathological phosphorylation of Tau protein in Alzheimer disease.
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MARKK, a Ste20-like kinase, activates the polarity-inducing kinase MARK/PAR-1
The EMBO journal, 2003Co-Authors: Thomas Timm, Eva-maria Mandelkow, Jacek Biernat, Jian Jiao, Joël VandekerckhoveAbstract:MARK, a kinase family related to PAR-1 involved in establishing cell polarity, phosphorylates microtubule-associated proteins (tau/MAP2/MAP4) at KXGS motifs, causes detachment from microtubules, and their disassembly. The sites are prominent in tau from Alzheimer's disease brains. We studied the activation of MARK and identified the upstream kinase, MARKK, a member of the Ste20 kinase family. It phosphorylates MARK within the activation loop (T208 in MARK2). A fraction of MARK in brain tissue is doubly phosphorylated (at T208/S212), reminiscent of the activation of MAP kinase; however, the phosphorylation of the second site in MARK (S212) is inhibitory. In cells the activity of MARKK enhances microtubule dynamics through the activation of MARK and leads to phosphorylation and detachment of tau or equivalent MAPs from microtubules. Overexpression of MARK eventually leads to microtubule breakdown and cell death, but in neuronal cells the primary effect is to allow the development of neurites during differentiation.
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Protein Kinase MARK/PAR-1 Is Required for Neurite Outgrowth and Establishment of Neuronal Polarity
Molecular biology of the cell, 2002Co-Authors: Jacek Biernat, Thomas Timm, Eva-maria Mandelkow, Qingyi Zheng-fischhöfer, Laurent MeijerAbstract:Protein kinases of the microtubule affinity-regulating kinase (MARK) family were originally discovered because of their ability to phosphorylate certain sites in tau protein (KXGS motifs in the repeat domain). This type of phosphorylation is enhanced in abnormal tau from Alzheimer brain tissue and causes the detachment of tau from microtubules. MARK-related kinases (PAR-1 and KIN1) occur in various organisms and are involved in establishing and maintaining cell polarity. Herein, we report the ability of MARK2 to affect the differentiation and outgrowth of cell processes from neuroblastoma and other cell models. MARK2 phosphorylates tau protein at the KXGS motifs; this results in the detachment of tau from microtubules and their destabilization. The formation of neurites in N2a cells is blocked if MARK2 is inactivated, either by transfecting a dominant negative mutant, or by MARK2 inhibitors such as hymenialdisine. Alternatively, neurites are blocked if the target KXGS motifs on tau are rendered nonphosphorylatable by point mutations. The results suggest that MARK2 contributes to the plasticity of microtubules needed for neuronal polarity and the growth of neurites.