title: Microtubule stabilization in vivo by nucleation-incompetent γ-tubulin complex.
abstract: Although the fission yeast Schizosaccharomyces pombe contains many of the γ-tubulin ring complex (γ-TuRC)-specific proteins of the γ-tubulin complex (γ-TuC), several questions about the organizational state and function of the fission yeast γ-TuC in vivo remain unresolved. Using 3×GFP-tagged γ-TuRC-specific proteins, we show here that γ-TuRC-specific proteins are present at all microtubule organizing centers in fission yeast and that association of γ-TuRC-specific proteins with the γ-tubulin small complex (γ-TuSC) does not depend on Mto1, which is a key regulator of the γ-TuC. Through sensitive imaging in mto1Δ mutants, in which cytoplasmic microtubule nucleation is abolished, we unexpectedly found that γ-TuC incapable of nucleating microtubules can nevertheless associate with microtubule minus-ends in vivo. The presence of γ-TuC at microtubule ends is independent of γ-TuRC-specific proteins and strongly correlates with the stability of microtubule ends. Strikingly, microtubule bundles lacking γ-TuC at microtubule ends undergo extensive treadmilling in vivo, apparently induced by geometrical constraints on plus-end growth. Our results indicate that microtubule stabilization by the γ-TuC, independently of its nucleation function, is important for maintaining the organization and dynamic behavior of microtubule arrays in vivo.
authors: Wellcome Trust Centre for Cell Biology, University of Edinburgh, Swann Building, Mayfield Road, Edinburgh EH9 3JR, UK.
authors: Andreas
authors: A
authors: Anders
authors: Kenneth E
authors: KE
authors: Sawin
mesh_terms: D022101:Microtubule-Organizing Center / Q000737:chemistry / Q000378:metabolism; D008870:Microtubules / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D011485:Protein Binding; D055550:Protein Stability; D012568:Schizosaccharomyces / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D029702:Schizosaccharomyces pombe Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D014404:Tubulin / Q000235:genetics / Q000378:metabolism*
chemical_list: D029702:Schizosaccharomyces pombe Proteins; D014404:Tubulin