Characterization of microtubule-associated protein phosphoisoforms present in isolated growth cones.
The presence of microtubule-associated proteins (MAPs) in growth cones has been analyzed by isolation of these structures and characterization of their proteins by immunofluorescence studies. Two major MAPs, MAP1B and tau, were present in growth cones of cerebellum neurons isolated from 5-day-old rats. Both MAPs could be modified by proline-dependent protein kinases (PDPK) with opposite effects. PDPK-modified MAP1B isoforms are present at the growth cones whereas PDPK-modified tau isoforms are absent. This result suggests a different role for each phosphoMAP. To look for a possible PDPK involved in the modification of MAP1B at the growth cone, the localization of MAP and cdc2 kinases was studied. Our results indicate that the distribution in neuronal cells of MAP kinase is compatible with a possible role of this protein in modifying MAP1B.
García Rocha
M
M
Centro de Biología Molecular Severo Ochoa Universidad Autónoma de Madrid, Spain.
Avila
J
J
D000818:Animals; D000918:Antibody Specificity; D001369:Axons / Q000502:physiology*; D016203:CDC2 Protein Kinase / Q000378:metabolism*; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000378:metabolism*; D002478:Cells, Cultured; D002531:Cerebellum / Q000737:chemistry* / Q000166:cytology; D008856:Microscopy, Fluorescence; D008869:Microtubule-Associated Proteins / Q000032:analysis*; D009474:Neurons / Q000737:chemistry* / Q000648:ultrastructure; D010766:Phosphorylation; D051381:Rats; D016875:tau Proteins / Q000032:analysis
D008869:Microtubule-Associated Proteins; C085284:microtubule-associated protein 1B; D016875:tau Proteins; D017871:Calcium-Calmodulin-Dependent Protein Kinases; D016203:CDC2 Protein Kinase