2000 Fiscal Year Final Research Report Summary
Regulation of chromosome segregation in the budding yeast, S.cerevisiae
| Project/Area Number |
11660093
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (C)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 一般 |
|---|
| Research Field |
応用微生物学・応用生物化学
|
|---|
| Research Institution | Hiroshima University |
|---|
Principal Investigator |
TSUCHIYA Eiko Hiroshima University, Graduate School of Advanced Sciences of Matter, professor, 大学院・先端物質科学研究科, 教授 (90127671)
|
|---|
| Project Period (FY) |
1999 – 2000
|
| Keywords | Saccharomyces cerevisiae / chromosome segregation / protein kinase C / microtuble-binding protein / chromatin-remodeling complex |
|---|
| Research Abstract |
NPS1/STH1 encodes a catalytic subunit of RSC and plays essential role for mitotic growth. Our previous analysis on temperature-sensitive mutant allele of NPS1, nps1-105, revealed that Nps1/RSC plays important role on the assembly and/or maintenance of the chromatin structure around centromeres. We performed this study on an attempt to understand the in vivo function of RSC and obtained the following results.
1) We isolated fifteen suppressor mutants (rtn mutants) that can restore the growth of nps1-105 in the presence of TBZ.These mutants were classified in nine complementation groups. Taking an advantage of temperature sensitivity, we cloned RTN2, RTN4 and RTN5 and identified them as NUP82, ABD1 and CET1, respectively.
2) We screened high-copy suppressor genes for the temperature- and thiabendazole (TBZ) nps1-105 mutant and identified nine genes including NPS1. Among those, PKC1 and BIM1 that respectively encoded a homolog of mammalian protein kinase C and a conserved microtubule binding protein homologous to human EB1 were found to play important role on suppression. Genetic analysis of the functional relationships between these genes revealed that PKC1 suppressed the defect of nps1-105 via the function of BIM1 but not through activation of the MPK1/MAPK pathway. The stt1 mutation showed TBZ sensitivity and delayed G2-phase progression at semi-permissive temperatures. Both of these stt1 phenotypes were suppressed by the overexpression of BIM1. In addition, stt1 as well as nps1-105, mis-segregated a mini-chromosome at higher frequency than the wild type at permissive temperature. The mis-segregation was enhanced in the nps1-105 stt1 double mutant. These results suggested that Pkc1p plays a role relevant to microtubule function and that this role is mediated by an unknown PKC effector branch and by Bim1p.
|
