Mal3 masks catastrophe events in Schizosaccharomyces pombe microtubules by inhibiting shrinkage and promoting rescue.

ABSTRACT: Schizosaccharomyces pombe Mal3 is a member of the EB family of proteins, which are proposed to be core elements in a tip-tracking network that regulates microtubule dynamics in cells. How Mal3 itself influences microtubule dynamics is unclear. We tested the effects of full-length recombinant Mal3 on dynamic microtubules assembled in vitro from purified S. pombe tubulin, using dark field video microscopy to avoid fluorescent tagging and data-averaging techniques to improve spatiotemporal resolution. We find that catastrophe occurs stochastically as a fast (<2.2 s) transition from constant speed growth to constant speed shrinkage with a constant probability that is independent of the Mal3 concentration. This implies that Mal3 neither stabilizes nor destabilizes microtubule tips. Mal3 does, h

SUBMITTER: Katsuki M 

PROVIDER: S-EPMC2764634 | biostudies-literature | 2009 Oct

REPOSITORIES: biostudies-literature