Format

Send to

Choose Destination
See comment in PubMed Commons below
EMBO J. 1996 Oct 1;15(19):5290-8.

Oncoprotein 18 is a phosphorylation-responsive regulator of microtubule dynamics.

Author information

  • 1Department of Cell and Molecular Biology, University of UmeĆ„, Sweden.

Abstract

Oncoprotein 18 (Op18, also termed p19, p18, prosolin or stathmin) is a cytosolic protein of previously unknown function. Phosphorylation of Op18 is cell cycle regulated by cyclin-dependent kinases (CDKs), and expression of a 'CDK target site-deficient mutant' results in a phenotype indicative of a role for Op18 during mitosis. This phenotype is compatible with the idea that Op18 is a phosphorylation-responsive regulator of microtubule (MT) dynamics. Therefore, in this study, we analyzed MTs in cells induced to express either wild-type or mutated Op18. The results showed that wild-type Op18 and a CDK target site mutant both efficiently elicited rapid depolymerization of MTs. This result contrasts with clear-cut differences in their cell cycle phenotypes. Morphological analysis of MTs explained this apparent discrepancy: while interphase MTs were depolymerized in cells expressing either Op18 derivative, apparently normal mitotic spindles were formed only in cells overexpressing wild-type Op18. This result correlates with our finding that only mutated Op18 causes a block during mitosis. Hence, we conclude that Op18 decreases MT stability and that this activity of Op18 is subject to cell cycle regulation by CDKs.

PMID:
8895574
PMCID:
PMC452273
[PubMed - indexed for MEDLINE]
Free PMC Article
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for PubMed Central
    Loading ...
    Support Center