Regulation and Localization of Mismatch Repair Proteins

Xavier University Of Louisiana, New Orleans LA

Investigators

Abstract

Abstract: An equipment supplement is requested to perform the experiments summarized below. This is necessary to perform the experiments outlined in the parent grant. DNA mismatch repair (MMR) is a highly conserved process. A functional MMR pathway is essential for maintaining genome integrity and loss of MMR results in genome instability and cancer in higher eukaryotes. For example, defects in MMR genes result in Lynch Syndrome, a common hereditary cancer syndrome resulting in early onset cancers of the colon, endometrium, ovaries, small intestine, hepatobiliary tract, and upper urinary tract as well as other tissues. In our most recent publication, we showed that deletion of Modulator of Transcription (Not4) and General Control Nonderepressible 5 (Gcn5) modulate the levels of MutSα (consisting of Msh2 and Msh6), the major complex involved in MMR. Not4 and Gcn5 are proteins that ubiquitylate and acetylate various proteins respectively. We hypothesize that these proteins modify MutSα and that the modifications affect the stability and localization of the complex. Further studies need to be conducted to gain a better understanding of how Not4 and Gcn5 regulate these MMR proteins. Additionally, our previous experiments have shown that yeast MutSα is in the vicinity of the replication machinery during DNA replication. Human MutSα interacts with the replication machinery by binding PCNA and also recognizes specific histone modifications. How yeast MutSα is recruited to chromatin remains elusive. Using the yeast Saccharomyces cerevisiae (S. cerevisiae), this project aims to: 1) further examine the role of Gcn5 and Not4 in the regulation of MutSα stability and 2) determine the effect of post-translational modifications on MMR protein recruitment to chromatin.