The selfish yeast plasmid uses the nuclear motor Kip1p but not Cin8p for its localization and equal segregation.
The 2 micron plasmid of Saccharomyces cerevisiae uses the Kip1 motor, but not the functionally redundant Cin8 motor, for its precise nuclear localization and equal segregation. The timing and lifetime of Kip1p association with the plasmid partitioning locus STB are consistent with Kip1p being an authentic component of the plasmid partitioning complex. Kip1-STB association is not blocked by disassembling the mitotic spindle. Lack of Kip1p disrupts recruitment of the cohesin complex at STB and cohesion of replicated plasmid molecules. Colocalization of a 2 micron reporter plasmid with Kip1p in close proximity to the spindle pole body is reminiscent of that of a CEN reporter plasmid. Absence of Kip1p displaces the plasmid from this nuclear address, where it has the potential to tether to a chromosome or poach chromosome segregation factors. Exploiting Kip1p, which is subsidiary to Cin8p for chromosome segregation, to direct itself to a "partitioning center" represents yet another facet of the benign parasitism of the yeast plasmid.
Section of Molecular Genetics and Microbiology, University of Texas at Austin, Austin, TX 78712, USA.
Hong
H
Cui
Santanu K
SK
Ghosh
Makkuni
M
Jayaram
D002453:Cell Cycle / Q000502:physiology; D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism; D002868:Chromosomal Proteins, Non-Histone / Q000235:genetics / Q000378:metabolism; D020090:Chromosome Segregation; D015825:Chromosomes, Fungal / Q000378:metabolism; D004271:DNA, Fungal / Q000235:genetics; D017930:Genes, Reporter; D016547:Kinesins; D008869:Microtubule-Associated Proteins / Q000235:genetics / Q000378:metabolism*; D020409:Molecular Motor Proteins; D015739:Nocodazole / Q000378:metabolism; D010957:Plasmids / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000166:cytology / Q000235:genetics / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism*; D008941:Spindle Apparatus / Q000378:metabolism; D015534:Trans-Activators / Q000235:genetics / Q000378:metabolism; D050257:Tubulin Modulators / Q000378:metabolism; D000097722:Cohesins
D018797:Cell Cycle Proteins; D002868:Chromosomal Proteins, Non-Histone; D004271:DNA, Fungal; D016547:Kinesins; D008869:Microtubule-Associated Proteins; D020409:Molecular Motor Proteins; D015739:Nocodazole; D029701:Saccharomyces cerevisiae Proteins; D015534:Trans-Activators; D050257:Tubulin Modulators; D000097722:Cohesins; C075342:CIN8 protein, S cerevisiae; C431747:KIP1 protein, S cerevisiae; C491137:REP1 protein, S cerevisiae; C490689:REP2 protein, S cerevisiae