Protein tyrosine phosphatases in Chaetopterus egg activation

Hinton, S. D., Yang, D. Z., Eckberg, W. R. (October 2003) Protein tyrosine phosphatases in Chaetopterus egg activation. Development Growth & Differentiation, 45 (5-6). pp. 405-415. ISSN 0012-1592

URL: http://www.ncbi.nlm.nih.gov/pubmed/14706066
DOI: 10.1111/j.1440-169X.2003.00707.x

Abstract

Changes in protein tyrosine phosphorylation are an essential aspect of egg activation after fertilization. Such changes result from the net contributions of both tyrosine kinases and phosphatases (PTP). This study was conducted to determine what role(s) PTP may have in egg activation. We identified four novel PTP in Chaetopterus pergamentaceus oocytes, cpPTPNT6, cpPTPNT7, cpPTPR2B, and cpPTPR2A, that have significant homology to, respectively, human PTPsigma, -rho, -D2 and -BAS. The first two are cytosolic and the latter two are transmembrane. Several PTP inhibitors were tested to see if they would affect Chaetopterus pergamentaceus fertilization. Eggs treated with beta-bromo-4-hydroxyacetophenone (PTP inhibitor 1) exhibited microvillar elongation, which is a sign of cortical changes resulting from activation. Those treated with Na3VO4 underwent full parthenogenetic activation, including polar body formation and pseudocleavage and did so independently of extracellular Ca2+, which is required for the Ca2+ oscillations that initiate development after fertilization, Fluorescence microscopy identified phosphotyrosine-containing proteins in the cortex and around the nucleus of vanadate-activated eggs, whereas in fertilized eggs they were concentrated only in the cortex. Immunoblots of vanadate-activated and fertilized eggs showed tyrosine hyperphosphorylation of approximately 140 kDa protein. These results suggest that PTP most likely maintain the egg in an inactive state by dephosphorylation of proteins independent of the Ca2+ oscillations in the activation process.

Item Type: Paper
Uncontrolled Keywords: egg activation fertilization invertebrate protein phosphorylation protein tyrosine phosphatase SEA-URCHIN EGG KINASE-ACTIVITY CYTOPLASMIC LOCALIZATION CAENORHABDITIS-ELEGANS FYN KINASE PTP-DELTA FERTILIZATION RECEPTOR CELL SRC
Subjects: bioinformatics > genomics and proteomics > genetics & nucleic acid processing
bioinformatics > genomics and proteomics
bioinformatics > genomics and proteomics > genetics & nucleic acid processing > protein structure, function, modification
bioinformatics > genomics and proteomics > genetics & nucleic acid processing > protein structure, function, modification > protein types > enzymes
bioinformatics > genomics and proteomics > genetics & nucleic acid processing > protein structure, function, modification > protein types > enzymes > protein phosphatase
bioinformatics > genomics and proteomics > genetics & nucleic acid processing > protein structure, function, modification > protein types
bioinformatics > genomics and proteomics > genetics & nucleic acid processing > protein structure, function, modification > protein types > enzymes > protein tyrosine phosphatase
CSHL Authors:
Communities: CSHL labs > Tonks lab
Depositing User: Matt Covey
Date: October 2003
Date Deposited: 27 Mar 2013 16:50
Last Modified: 27 Mar 2013 16:50
Related URLs:
URI: http://repository.cshl.edu/id/eprint/28025

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