Two Saccharomyces cerevisiae kinesin-related gene products required for mitotic spindle assembly.
Two Saccharomyces cerevisiae genes, CIN8 and KIP1 (a.k.a. CIN9), were identified by their requirement for normal chromosome segregation. Both genes encode polypeptides related to the heavy chain of the microtubule-based force-generating enzyme kinesin. Cin8p was found to be required for pole separation during mitotic spindle assembly at 37 degrees C, although overproduced Kip1p could substitute. At lower temperatures, the activity of at least one of these proteins was required for cell viability, indicating that they perform an essential but redundant function. Cin8p was observed to be a component of the mitotic spindle, colocalizing with the microtubules that lie between the poles. Taken together, these findings suggest that these proteins interact with spindle microtubules to produce an outwardly directed force acting upon the poles.
Hoyt
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MA
Department of Biology, Johns Hopkins University, Baltimore, Maryland 21218.
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Loo
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Saunders
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D000595:Amino Acid Sequence; D001483:Base Sequence; D002455:Cell Division / Q000235:genetics; D002872:Chromosome Deletion; D005455:Fluorescent Antibody Technique; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism*; D016547:Kinesins / Q000235:genetics / Q000378:metabolism*; D008869:Microtubule-Associated Proteins / Q000235:genetics / Q000378:metabolism*; D008938:Mitosis / Q000235:genetics; D020409:Molecular Motor Proteins; D008969:Molecular Sequence Data; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism* / Q000648:ultrastructure; D029701:Saccharomyces cerevisiae Proteins; D012689:Sequence Homology, Nucleic Acid; D008941:Spindle Apparatus / Q000378:metabolism*; D014404:Tubulin / Q000302:isolation & purification
C075342:CIN8 protein, S cerevisiae; D005656:Fungal Proteins; C431747:KIP1 protein, S cerevisiae; D008869:Microtubule-Associated Proteins; D020409:Molecular Motor Proteins; D029701:Saccharomyces cerevisiae Proteins; D014404:Tubulin; D016547:Kinesins