Gamma-tubulin complex-mediated anchoring of spindle microtubules to spindle-pole bodies requires Msd1 in fission yeast.
The anchoring of microtubules to subcellular structures is critical for cell polarity and motility. Although the process of anchoring cytoplasmic microtubules to the centrosome has been studied in some detail, it is not known how spindle microtubules are anchored to the mitotic centrosome and, particularly, whether anchoring and nucleation of mitotic spindles are functionally separate. Here, we show that a fission yeast coiled-coil protein, Msd1, is required for anchoring the minus end of spindle microtubules to the centrosome equivalent, the spindle-pole body (SPB). msd1 deletion causes spindle microtubules to abnormally extend beyond SPBs, which results in chromosome missegregation. Importantly, this protruding spindle is phenocopied by the amino-terminal deletion mutant of Alp4, a component of the gamma-tubulin complex (gamma-TuC), which lacks the potential Msd1-interacting domain. We propose that Msd1 interacts with gamma-TuC, thereby specifically anchoring the minus end of microtubules to SPBs without affecting microtubule nucleation.
Toya
Mika
M
Laboratory of Cell Regulation, Cancer Research UK, London Research Institute, Lincoln's Inn Fields Laboratories, 44 Lincoln's Inn Fields, London WC2A 3PX, UK.
Sato
Masamitsu
M
Haselmann
Uta
U
Asakawa
Kazuhide
K
Brunner
Damian
D
Antony
Claude
C
Toda
Takashi
T
D018385:Centrosome / Q000378:metabolism / Q000648:ultrastructure; D020090:Chromosome Segregation / Q000502:physiology; D046529:Microscopy, Electron, Transmission; D008869:Microtubule-Associated Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D008870:Microtubules / Q000378:metabolism* / Q000648:ultrastructure; D008938:Mitosis / Q000502:physiology*; D017434:Protein Structure, Tertiary / Q000502:physiology; D012568:Schizosaccharomyces / Q000235:genetics / Q000378:metabolism* / Q000648:ultrastructure; D029702:Schizosaccharomyces pombe Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D008941:Spindle Apparatus / Q000378:metabolism* / Q000648:ultrastructure; D014404:Tubulin / Q000378:metabolism*
C512340:Alp4 protein, S pombe; D008869:Microtubule-Associated Proteins; C521127:Msd1 protein, S pombe; D029702:Schizosaccharomyces pombe Proteins; D014404:Tubulin