EXPLORING THE INTERACTION BETWEEN SGS1 AND TOP3

探索SGS1与TOP3之间的互动

• 批准号: 6294838
• 负责人: MARISA WAGNER
• 金额: $ 4.02万
• 依托单位: COLUMBIA UNIVERSITY HEALTH SCIENCES
• 依托单位国家: 美国
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-04-01 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/6294838
• 关键词: DNA replication; DNA topoisomerases; cell cycle; chemical carcinogen; chemical carcinogenesis; chimeric proteins; chromatin; enzyme activity; genetic recombination; green fluorescent proteins; helicase; immunoprecipitation; mutagens; point mutation; recombinant proteins; tissue /cell culture

Human diseases that enhance cancer predisposition are associated with increased chromosome rearrangements. Yeast homologs have been found for a number of these disease genes and mutation of the yeast gene shown to cause hyper-recombination. Study of such yeast hyper- recombination mutants will lend insight to the disease processes and cancer etiology in general. The S. cerevisiae Sgs1 DNA helicase is highly homologous to the proteins which are mutated in the Wenner, Bloom and Rothmund-Thomson cancer predisposition syndromes. Sgs1 mutants were identified as suppressors of the slow growth of top3 DNA topoisomerase mutants. top3 mutants exhibit pleiotropic defects including hyper-recombination. The sgsl mutant phenotype is reminiscent of top3, albeit generally less severe. SGS1 epistasis to TOPS indicates that they function in the same pathway. In addition to Top3, yeast also contain the Top1 and Top2 topoisomerases. In pairwise combinations, the three topoisomerases exhibit synergistc defects indicating functional overlaps. Sgs1 physically interacts with Top2 and Top3. sgsl in combination with either topl or top2 mutation exhibits synergistic defects. The functional overlaps/antagonisms among Sgs1/Top3 and the other topoisomerases are not understood. The DNA substrates upon which Sgs1 and Top3 act in vivo are not known. Interestingly, Sgs1/Top3 interaction is conserved in humans. The knowledge of when and where Sgs1 and Top3 act during DNA replication/recombination in yeast can lend important insight to the human disease process and cancer etiology. The goal of this proposal is to investigate the functions of Sgs1 and Top3 in S. cerevisiae using combined genetic, biochemical, and cell biological approaches.

增强癌症易感性的人类疾病与染色体重排的增加有关。已经发现了许多这些疾病基因的酵母同源物，以及显示出过度重组的酵母基因的突变。对这种酵母超重组突变体的研究将为疾病过程和癌症病因提供洞察力。酿酒酵母SGS1 DNA解旋酶与Wenner，Bloom和Rothmund-Thomson Cancer Cancer Cancer倾向综合症中突变的蛋白质高度同源。 SGS1突变体被确定为TOP3 DNA拓扑异构酶突变体缓慢生长的抑制剂。 TOP3突变体表现出多效缺陷，包括过度重组。 SGSL突变体表型让人联想到TOP3，尽管通常不那么严重。 sgs1上位到顶部表明它们在同一途径中起作用。除TOP3外，酵母还包含TOP1和TOP2拓扑异构酶。在成对组合中，三个拓扑异构酶表现出协同的缺陷，表明功能重叠。 SGS1与TOP2和TOP3物理相互作用。 SGSL与TOPL或TOP2突变相结合表现出协同缺陷。 SGS1/TOP3和其他拓扑异构酶之间的功能重叠/拮抗作用尚不清楚。尚不清楚SGS1和TOP3 ACT的DNA底物。有趣的是，SGS1/TOP3相互作用在人类中是保守的。在酵母中DNA复制/重组过程中SGS1和TOP3在何时何地进行的知识可以为人类疾病过程和癌症病因提供重要的见解。该提案的目的是使用遗传，生化和细胞生物学方法研究SGS1和TOP3在酿酒酵母中的功能。