Dis3, implicated in mitotic control, binds directly to Ran and enhances the GEF activity of RCC1

摘要: Using the two-hybrid method, we isolated a Saccharomyces cerevisiae cDNA encoding protein homologous to Schizosaccharomyces pombe Dis3sp, using as bait, human GTPase Ran. The DIS3 gene is essential for viability and complements S.pombe mutant dis3-54 which defective in mitosis. Although Dis3sc has no homology RanBP1, it bound directly Ran S.cerevisiae homologue Cnr1, but not RCC1 Srm1. Upon binding with 1:1 molar ratio, enhanced nucleotide-releasing activity of on In presence Dis3sc, K(m) decreased by half, while kcat was unchanged. vivo, Dis3sp present oligomers M(r) 670-200 kDa previously reported, 200 oligomer found include Spi1 Pim1, homologues RCC1, respectively. biological function heterotrimeric consisting Dis3, Pim1 unknown, our results indicate that Dis3 component RCC1-Ran pathway.