Abstract

Role of Base Excision Repair Enzyme MUTYH in the Repair of 8-Hydroxyguanine and MUTYH-Associated Polyposis (MAP)

Kazuya Shinmura, Masanori Goto, Hong Tao and Haruhiko Sugimura

Abstract
8-Hydroxyguanine (8OHG) is an oxidized form of guanine, and the formation of 8OHG in DNA causes a G:C to T:A transversion mutation, since 8OHG can pair with adenine as well as cytosine. The base excision repair gene MUTYH encodes a DNA glycosylase for adenine mispaired with 8OHG and is thus involved in the prevention of mutations caused by 8OHG. Biallelic mutations of the MUTYH gene are responsible for MUTYH-associated polyposis (MAP), which is a hereditary disease and is characterized by a predisposition to multiple colorectal adenomas and carcinomas. This article reviews the repair function of MUTYH towards 8OHG, the functional characterization of MUTYH variants, the characteristics of MAP tumors, and the management of MAP patients.