S. Sazer et P. Nurse, A FISSION YEAST RCC1-RELATED PROTEIN IS REQUIRED FOR THE MITOSIS TO INTERPHASE TRANSITION, EMBO journal, 13(3), 1994, pp. 606-615
The isolation and characterization of the mutant dcd(ts) (defect in ch
romatin decondensation) has led to the identification of two conserved
proteins required for the re-establishment of the interphase state fo
llowing the completion of mitosis. The gene that rescues the dcd(ts) m
utant encodes a protein similar to the human chromatin binding protein
, RCC1. A suppressor of dcd(ts) encodes a protein nearly identical to
the human GTP-binding protein, RAN, encoded by the TC4 gene. These res
ults indicate that completion of mitosis is regulated at least in part
by a GTPase molecular switch. The gene and suppressor of dcd(ts) are
identical to the previously described Schizosaccharomyces pombe genes
pim1 (premature initiation of mitosis) and spi1 (suppressor of pim), b
ut the dcd(ts) mutant does not enter mitosis prematurely, a phenotype
that has been reported for the pim1-46ts mutant. Based on our studies
we propose that the pim1 gene product is required for regulating chrom
atin condensation with a primary role at the end of mitosis and pleiot
ropic effects on other aspects of cell behavior.