The protein kinase kin1 is required for cellular symmetry in fission yeast.
The fission yeast Schizosaccharomyces pombe is a highly polarized unicellular eukaryote with two opposite growing poles in which F-actin cytoskeleton is focused. The KIN1/PAR-1/MARK protein family is composed of conserved eukaryotic serine/threonine kinases which are involved in cell polarity, microtubule stability or cell cycle regulation. Here, we investigate the function of the fission yeast KIN1/PAR-1/MARK member, kin1p. Using a deletion allele (kin1Delta), we show that kin1 mutation promotes a delay in septation. Kin1p regulates the structure of the new cell end after cytokinesis by modulating cell wall remodeling. Abnormal shaped interphase kin1Delta cells misplace F-actin patches and the premitotic nucleus. Thus, mitotic kin1Delta cells misposition the F-actin ring assembly site that is dependent on the position of the interphase nucleus. The resulting asymmetric cell division produces daughter cells with distinct shapes. Overexpressed kin1p accumulates asymmetrically at the cell cortex and affects cell shape, F-actin organization and microtubules. Our results suggest that correct dosage of kin1p at the cortex is required for spatial organization of the fission yeast cell.
La Carbona
Stéphanie
S
UMR6061 Génétique et Développement, CNRS/Université de Rennes 1, Faculté de Médecine 35043 Rennes cedex France.
Allix
Caroline
C
Philippe
Michel
M
Le Goff
Xavier
X
D000199:Actins / Q000378:metabolism; D002455:Cell Division / Q000502:physiology; D016764:Cell Polarity; D048429:Cell Size; D002473:Cell Wall / Q000187:drug effects; D003599:Cytoskeleton / Q000378:metabolism; D006867:Hydrolases / Q000494:pharmacology; D007399:Interphase; D008870:Microtubules / Q000378:metabolism; D009154:Mutation / Q000235:genetics; D010750:Phosphoproteins; D017346:Protein Serine-Threonine Kinases / Q000235:genetics / Q000378:metabolism*; D011506:Proteins / Q000235:genetics / Q000378:metabolism*; D011994:Recombinant Proteins / Q000378:metabolism; D012568:Schizosaccharomyces / Q000166:cytology* / Q000187:drug effects / Q000201:enzymology* / Q000235:genetics; D029702:Schizosaccharomyces pombe Proteins; D014162:Transfection
D000199:Actins; D010750:Phosphoproteins; D011506:Proteins; D011994:Recombinant Proteins; D029702:Schizosaccharomyces pombe Proteins; C037833:zymolyase; D017346:Protein Serine-Threonine Kinases; C087571:kin1 protein, S pombe; D006867:Hydrolases