title: Rsp1p, a J domain protein required for disassembly and assembly of microtubule organizing centers during the fission yeast cell cycle.
abstract: Regulation of microtubule organizing centers (MTOCs) orchestrates the reorganization of the microtubule (MT) cytoskeleton. In the fission yeast Schizosaccharomyces pombe, an equatorial MTOC (eMTOC) at the cell division site disassembles after cytokinesis, and multiple interphase MTOCs (iMTOCs) appear on the nucleus. Here, we show that, upon eMTOC disassembly, small satellites carrying MTOC components such as the gamma-tubulin complex travel in both directions along interphase MTs. We identify rsp1p, an MTOC protein required for eMTOC disassembly. In rsp1 loss-of-function mutants, the eMTOC persists and organizes an abnormal microtubule aster, while iMTOCs and satellites are greatly reduced. Conversely, rsp1p overexpression inhibits eMTOC formation. Rsp1p is a J domain protein that interacts with an hsp70. Thus, our findings suggest a model in which rsp1p is part of a chaperone-based mechanism that disassembles the eMTOC into satellites, contributing to the dynamic redistribution of MTOC components for organization of interphase microtubules.
authors.affiliation: Department of Microbiology, College of Physicians and Surgeons, Columbia University, 701 West 168th Street, New York, NY 10032, USA.
authors.forename: Sabina
authors.initials: S
authors.lastname: Zimmerman
authors.forename: P T
authors.initials: PT
authors.lastname: Tran
authors.forename: Rafael R
authors.initials: RR
authors.lastname: Daga
authors.forename: Osami
authors.initials: O
authors.lastname: Niwa
authors.forename: Fred
authors.initials: F
authors.lastname: Chang
mesh_terms: D000595:Amino Acid Sequence / Q000235:genetics; D001483:Base Sequence / Q000235:genetics; D002453:Cell Cycle / Q000235:genetics*; D018076:DNA, Complementary / Q000032:analysis / Q000235:genetics; D015966:Gene Expression Regulation, Fungal / Q000235:genetics; D018840:HSP70 Heat-Shock Proteins / Q000378:metabolism; D008869:Microtubule-Associated Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D022101:Microtubule-Organizing Center / Q000378:metabolism*; D008870:Microtubules / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D009154:Mutation / Q000235:genetics; D010641:Phenotype; D017434:Protein Structure, Tertiary / Q000235:genetics; D012568:Schizosaccharomyces / Q000235:genetics / Q000378:metabolism*; D029702:Schizosaccharomyces pombe Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*
chemical_list: D018076:DNA, Complementary; D018840:HSP70 Heat-Shock Proteins; D008869:Microtubule-Associated Proteins; C486130:Rsp1 protein, S pombe; D029702:Schizosaccharomyces pombe Proteins