Identification of Proteins That Interact with Sacchromyces cerevisiae Cdc13p by Synthetic Lethal Screening

• Main Authors: Te-Ling Pang, 龐德玲
• Other Authors: Jing-Jer Lin
• Format: Others
• Language: zh-TW
• Published: 2000
• Online Access: http://ndltd.ncl.edu.tw/handle/14435079250040677045

碩士 === 國立陽明大學 === 生物藥學研究所 === 88 === Telomeres are the specialized DNA-protein structures that comprise the chromosome and allow the complete replication of chromosomes. In Saccharomyces cerevisiae, the telomere sequence is composed of a ~300bp of C1-3A/TG1-3 repeats plus a short single-strand TG1-3 tail. Cdc13p binds to the yeast single-strand TG1-3 telomere DNA sequence thus protects telomere and regulates telomere length. CDC13 is an essential gene. A temperature sensitive allele of CDC13, cdc13-1, causes cell arrest in the G2/M phase of the cell cycle at non-permissive temperature suggested that Cdc13p is involved in cell cycle control. Cdc13p also regulates the length of telomeres since a mutation allele of CDC13, cdc13-2, causes gradual loss of telomere length. To identify genes that interact with CDC13, a synthetic lethal screening strategy was applied. Synthetic lethal is a term describes two mutants that individual is not lethal but together are lethal to cells. Mutation on two genes that cause synthetic lethality indicates that these two genes are genetically related. Using this method, we have identified a mutation on NAT1 that was synthetic lethal to cdc13-1. NAT1 is the catalytic subunit of protein N-acetyltransferase and is required for transcriptional silencing at the telomere. Here, we showed that NAT1 and CDC13 interacted genetically. In addition, using a yeast two-hybrid system, we showed Nat1p interacted weakly with the N-terminal 1-252 amino acids of Cdc13p.