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Annalisa Calcagno - One of the best experts on this subject based on the ideXlab platform.
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early onset central diabetes insipidus is associated with de novo arginine vasopressin neurophysin ii or wolfram syndrome 1 gene mutations
European Journal of Endocrinology, 2015Co-Authors: Silverio Perrotta, Natascia Di Iorgi, Fulvio Della Ragione, Saverio Scianguetta, Adriana Borriello, Anna Elsa Maria Allegri, Marcella Ferraro, Claudia Santoro, Flavia Napoli, Annalisa CalcagnoAbstract:Objective: Idiopathic early-onset central diabetes insipidus (CDI) might be due to mutations of arginine vasopressin– neurophysin II (AVP–NPII (AVP)) or wolframin (WFS1) genes. Design and methods: Sequencing of AVP and WFS1 genes was performed in nine children with CDI, aged between 9 and 68 months, and negative family history for polyuria and polydipsia. Results: Two patients carried a mutation in the AVP gene: a heterozygous G-to-T transition at nucleotide position 322 of exon 2 (c.322GOT) resulting in a stop codon at position 108 (p.Glu108X), and a novel deletion from nucleotide 52 to 54 (c.52_54delTCC) producing a deletion of a serine at position 18 (p.Ser18del) of the AVP pre-prohormone signal peptide. A third patient carried two heterozygous mutations in the WFS1 gene localized on different alleles. The first change was A-to-G transition at nucleotide 997 in exon 8 (c.997AOG), resulting in a Valine Residue at position 333 in place of isoleucine (p.Ile333Val). The second novel mutation was a 3 bp insertion in exon 8, c.2392_2393insACG causing the addition of an aspartate Residue at position 797 and the maintenance of the correct open reading frame (p. Asp797_Val798insAsp). While similar WFS1 protein levels were detected in fibroblasts from healthy subjects and from the patient and his parents, a major sensitivity to staurosporine-induced apoptosis was observed in the patient fibroblasts as well as in patients with Wolfram syndrome. Conclusions: Early-onset CDI is associated with de novo mutations of the AVP gene and with hereditary WFS1 gene changes. These findings have valuable implications for management and genetic counseling.
David L Stokes - One of the best experts on this subject based on the ideXlab platform.
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the transmembrane domain of the p75 neurotrophin receptor stimulates phosphorylation of the trkb tyrosine kinase receptor
Journal of Biological Chemistry, 2017Co-Authors: Khalil Saadipour, Michael Maclean, Sean Pirkle, Solav Ali, Maria Luisa Lopezredondo, David L StokesAbstract:The function of protein products generated from intramembraneous cleavage by the γ-secretase complex is not well defined. The γ-secretase complex is responsible for the cleavage of several transmembrane proteins, most notably the amyloid precursor protein that results in Aβ, a transmembrane (TM) peptide. Another protein that undergoes very similar γ-secretase cleavage is the p75 neurotrophin receptor. However, the fate of the cleaved p75 TM domain is unknown. p75 neurotrophin receptor is highly expressed during early neuronal development and regulates survival and process formation of neurons. Here, we report that the p75 TM can stimulate the phosphorylation of TrkB (tyrosine kinase receptor B). In vitro phosphorylation experiments indicated that a peptide representing p75 TM increases TrkB phosphorylation in a dose- and time-dependent manner. Moreover, mutagenesis analyses revealed that a Valine Residue at position 264 in the rat p75 neurotrophin receptor is necessary for the ability of p75 TM to induce TrkB phosphorylation. Because this Residue is just before the γ-secretase cleavage site, we then investigated whether the p75(αγ) peptide, which is a product of both α- and γ-cleavage events, could also induce TrkB phosphorylation. Experiments using TM domains from other receptors, EGFR and FGFR1, failed to stimulate TrkB phosphorylation. Co-immunoprecipitation and biochemical fractionation data suggested that p75 TM stimulates TrkB phosphorylation at the cell membrane. Altogether, our results suggest that TrkB activation by p75(αγ) peptide may be enhanced in situations where the levels of the p75 receptor are increased, such as during brain injury, Alzheimer's disease, and epilepsy.
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the transmembrane domain of the p75 neurotrophin receptor stimulates phosphorylation of the trkb tyrosine kinase receptor
Journal of Biological Chemistry, 2017Co-Authors: Khalil Saadipour, Michael Maclean, Sean Pirkle, Maria Luisa Lopezredondo, David L Stokes, Moses V ChaoAbstract:Abstract The function of protein products generated from intramembraneous cleavage by the γ-secretase complex is not well defined. The γ-secretase complex is responsible for the cleavage of several transmembrane proteins, most notably the amyloid precursor protein which results in Aβ, a transmembrane (TM) peptide. Another protein that undergoes a very similar γ-secretase cleavage is the p75 neurotrophin receptor. However, the fate of the cleaved p75 TM domain is unknown. p75 neurotrophin receptor is highly expressed during early neuronal development and regulates survival and process formation of neurons. Here, we report that the p75 TM can stimulate the phosphorylation of the tyrosine kinase receptor B (TrkB). In vitro phosphorylation experiments indicated that a peptide representing p75 TM increases TrkB phosphorylation in a dose- and time- dependent manner. Moreover, mutagenesis analyses revealed that a Valine Residue at position 264 in the rat p75 neurotrophin receptor is necessary for the ability of p75 TM to induce TrkB phosphorylation. Since this Residue is immediately after the γ-secretase cleavage site, we then examined if the p75(αγ) peptide, which is a product of both α- and γ- cleavage events, could also induce TrkB phosphorylation. Experiments using TM domains from other receptors, EGFR and FGFR1, failed to stimulate TrkB phosphorylation. Co-immunoprecipitation and biochemical fractionation data suggested that p75 TM stimulates TrkB phosphorylation at the cell membrane. Altogether our results suggest that TrkB activation by p75(αγ) peptide may be enhanced in situations where the levels of the p75 receptor are increased, such as during brain injury, Alzheimers disease, and epilepsy.
Silverio Perrotta - One of the best experts on this subject based on the ideXlab platform.
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early onset central diabetes insipidus is associated with de novo arginine vasopressin neurophysin ii or wolfram syndrome 1 gene mutations
European Journal of Endocrinology, 2015Co-Authors: Silverio Perrotta, Natascia Di Iorgi, Fulvio Della Ragione, Saverio Scianguetta, Adriana Borriello, Anna Elsa Maria Allegri, Marcella Ferraro, Claudia Santoro, Flavia Napoli, Annalisa CalcagnoAbstract:Objective: Idiopathic early-onset central diabetes insipidus (CDI) might be due to mutations of arginine vasopressin– neurophysin II (AVP–NPII (AVP)) or wolframin (WFS1) genes. Design and methods: Sequencing of AVP and WFS1 genes was performed in nine children with CDI, aged between 9 and 68 months, and negative family history for polyuria and polydipsia. Results: Two patients carried a mutation in the AVP gene: a heterozygous G-to-T transition at nucleotide position 322 of exon 2 (c.322GOT) resulting in a stop codon at position 108 (p.Glu108X), and a novel deletion from nucleotide 52 to 54 (c.52_54delTCC) producing a deletion of a serine at position 18 (p.Ser18del) of the AVP pre-prohormone signal peptide. A third patient carried two heterozygous mutations in the WFS1 gene localized on different alleles. The first change was A-to-G transition at nucleotide 997 in exon 8 (c.997AOG), resulting in a Valine Residue at position 333 in place of isoleucine (p.Ile333Val). The second novel mutation was a 3 bp insertion in exon 8, c.2392_2393insACG causing the addition of an aspartate Residue at position 797 and the maintenance of the correct open reading frame (p. Asp797_Val798insAsp). While similar WFS1 protein levels were detected in fibroblasts from healthy subjects and from the patient and his parents, a major sensitivity to staurosporine-induced apoptosis was observed in the patient fibroblasts as well as in patients with Wolfram syndrome. Conclusions: Early-onset CDI is associated with de novo mutations of the AVP gene and with hereditary WFS1 gene changes. These findings have valuable implications for management and genetic counseling.
M Arslankirchner - One of the best experts on this subject based on the ideXlab platform.
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mutation screening of the fibrillin 1 fbn1 gene in 76 unrelated patients with marfan syndrome or marfanoid features leads to the identification of 11 novel and three previously reported mutations
Human Mutation, 2002Co-Authors: Kathrin Rommel, Matthias Karck, Axel Haverich, Jorg Schmidtke, M ArslankirchnerAbstract:Mutations in the gene encoding fibrillin-1 (FBN1) cause Marfan syndrome (MFS) and other related connective tissue disorders. In this study we performed SSCP to analyze all 65 exons of the FBN1 gene in 76 patients presenting with classical MFS or related phenotypes. We report 7 missense mutations, 3 splice site alterations, one indel mutation, one nonsense mutation and two mutations causing frameshifts: a 16bp deletion and a single nucleotide insertion. 5 of the missense mutations (Y1101C, C1806Y, T1908I, G1919D, C2251R) occur in calcium-binding Epidermal Growth Factor-like (EGFcb) domains of exons 26, 43, 46 and 55, respectively. One missense mutation (V449I) substitutes a Valine Residue in the non-calcium-binding epidermal growth factor like domain (EGFncb) of exon 11. One missense mutation (G880S) affects the “hybrid” motif in exon 21 by replacing glycine to serine. The 3 splice site mutations detected are: IVS1–1G>A in intron 1, IVS38-1G>A in intron 38 and IVS46+5G>A in intron 46. C628delinsK was identified in exon 15 leading to the substitution of a conserved cysteine Residue. Furthermore two frameshift mutations were found in exon 15 (1904-1919del ) and exon 63 (8025insC) leading to premature termination codons (PTCs) in exon 17 and 64 respectively. Finally we identified a nonsense mutation (R429X) located in the proline rich domain in exon 10 of the FBN1 gene. Y1101C, IVS46+5G>A and R429X have been reported before. © 2002 Wiley-Liss, Inc.
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mutation screening of the fibrillin 1 fbn1 gene in 76 unrelated patients with marfan syndrome or marfanoid features leads to the identification of 11 novel and three previously reported mutations
Human Mutation, 2002Co-Authors: Kathrin Rommel, Matthias Karck, Axel Haverich, Jorg Schmidtke, M ArslankirchnerAbstract:Mutations in the gene encoding fibrillin-1 (FBN1) cause Marfan syndrome (MFS) and other related connective tissue disorders. In this study we performed SSCP to analyze all 65 exons of the FBN1 gene in 76 patients presenting with classical MFS or related phenotypes. We report 7 missense mutations, 3 splice site alterations, one indel mutation, one nonsense mutation and two mutations causing frameshifts: a 16bp deletion and a single nucleotide insertion. 5 of the missense mutations (Y1101C, C1806Y, T1908I, G1919D, C2251R) occur in calcium-binding Epidermal Growth Factor-like (EGFcb) domains of exons 26, 43, 46 and 55, respectively. One missense mutation (V449I) substitutes a Valine Residue in the non-calcium-binding epidermal growth factor like domain (EGFncb) of exon 11. One missense mutation (G880S) affects the "hybrid" motif in exon 21 by replacing glycine to serine. The 3 splice site mutations detected are: IVS1-1G>A in intron 1, IVS38-1G>A in intron 38 and IVS46+5G>A in intron 46. C628delinsK was identified in exon 15 leading to the substitution of a conserved cysteine Residue. Furthermore two frameshift mutations were found in exon 15 (1904-1919del ) and exon 63 (8025insC) leading to premature termination codons (PTCs) in exon 17 and 64 respectively. Finally we identified a nonsense mutation (R429X) located in the proline rich domain in exon 10 of the FBN1 gene. Y1101C, IVS46+5G>A and R429X have been reported before.
Khalil Saadipour - One of the best experts on this subject based on the ideXlab platform.
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the transmembrane domain of the p75 neurotrophin receptor stimulates phosphorylation of the trkb tyrosine kinase receptor
Journal of Biological Chemistry, 2017Co-Authors: Khalil Saadipour, Michael Maclean, Sean Pirkle, Solav Ali, Maria Luisa Lopezredondo, David L StokesAbstract:The function of protein products generated from intramembraneous cleavage by the γ-secretase complex is not well defined. The γ-secretase complex is responsible for the cleavage of several transmembrane proteins, most notably the amyloid precursor protein that results in Aβ, a transmembrane (TM) peptide. Another protein that undergoes very similar γ-secretase cleavage is the p75 neurotrophin receptor. However, the fate of the cleaved p75 TM domain is unknown. p75 neurotrophin receptor is highly expressed during early neuronal development and regulates survival and process formation of neurons. Here, we report that the p75 TM can stimulate the phosphorylation of TrkB (tyrosine kinase receptor B). In vitro phosphorylation experiments indicated that a peptide representing p75 TM increases TrkB phosphorylation in a dose- and time-dependent manner. Moreover, mutagenesis analyses revealed that a Valine Residue at position 264 in the rat p75 neurotrophin receptor is necessary for the ability of p75 TM to induce TrkB phosphorylation. Because this Residue is just before the γ-secretase cleavage site, we then investigated whether the p75(αγ) peptide, which is a product of both α- and γ-cleavage events, could also induce TrkB phosphorylation. Experiments using TM domains from other receptors, EGFR and FGFR1, failed to stimulate TrkB phosphorylation. Co-immunoprecipitation and biochemical fractionation data suggested that p75 TM stimulates TrkB phosphorylation at the cell membrane. Altogether, our results suggest that TrkB activation by p75(αγ) peptide may be enhanced in situations where the levels of the p75 receptor are increased, such as during brain injury, Alzheimer's disease, and epilepsy.
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the transmembrane domain of the p75 neurotrophin receptor stimulates phosphorylation of the trkb tyrosine kinase receptor
Journal of Biological Chemistry, 2017Co-Authors: Khalil Saadipour, Michael Maclean, Sean Pirkle, Maria Luisa Lopezredondo, David L Stokes, Moses V ChaoAbstract:Abstract The function of protein products generated from intramembraneous cleavage by the γ-secretase complex is not well defined. The γ-secretase complex is responsible for the cleavage of several transmembrane proteins, most notably the amyloid precursor protein which results in Aβ, a transmembrane (TM) peptide. Another protein that undergoes a very similar γ-secretase cleavage is the p75 neurotrophin receptor. However, the fate of the cleaved p75 TM domain is unknown. p75 neurotrophin receptor is highly expressed during early neuronal development and regulates survival and process formation of neurons. Here, we report that the p75 TM can stimulate the phosphorylation of the tyrosine kinase receptor B (TrkB). In vitro phosphorylation experiments indicated that a peptide representing p75 TM increases TrkB phosphorylation in a dose- and time- dependent manner. Moreover, mutagenesis analyses revealed that a Valine Residue at position 264 in the rat p75 neurotrophin receptor is necessary for the ability of p75 TM to induce TrkB phosphorylation. Since this Residue is immediately after the γ-secretase cleavage site, we then examined if the p75(αγ) peptide, which is a product of both α- and γ- cleavage events, could also induce TrkB phosphorylation. Experiments using TM domains from other receptors, EGFR and FGFR1, failed to stimulate TrkB phosphorylation. Co-immunoprecipitation and biochemical fractionation data suggested that p75 TM stimulates TrkB phosphorylation at the cell membrane. Altogether our results suggest that TrkB activation by p75(αγ) peptide may be enhanced in situations where the levels of the p75 receptor are increased, such as during brain injury, Alzheimers disease, and epilepsy.
