Analysis of structure and microtubule assembly activity of the Drosophila 205K MAP.
Phosphorylation, dimerization and binding to calmodulin have been reported to influence the microtubule assembly capacities of MAPs (microtubule-associated proteins). Here we report that the Drosophila 205K MAP is a phosphoprotein in vivo and can be phosphorylated by cdc2/p34 in vitro. Bacterially produced 205K MAP is competent of microtubule assembly and microtubule bundling and binds to immobilized calmodulin in a Ca2+-dependent way. EM rotary shadowing analyses suggest that 205K MAP consists of an amino-terminal flexible extended region and a carboxy-terminal globular domain. This carboxy-terminal region harbors the microtubule binding site and sequences required for dimerization, as confirmed by in vitro crosslinking experiments of truncated proteins.
Irminger-Finger
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Division of Oncology, University of Geneva Medical Center, Switzerland.
Ortega Perez
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D000818:Animals; D003432:Cross-Linking Reagents / Q000737:chemistry; D019281:Dimerization; D004330:Drosophila; D008869:Microtubule-Associated Proteins / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism; D008870:Microtubules / Q000378:metabolism*; D010766:Phosphorylation; D011485:Protein Binding; D011487:Protein Conformation; D011994:Recombinant Proteins / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism; D013552:Swine; D014404:Tubulin / Q000378:metabolism
D003432:Cross-Linking Reagents; D008869:Microtubule-Associated Proteins; D011994:Recombinant Proteins; D014404:Tubulin