HS1 and EMS1

Abstract

Both HS1(hematopoiesis specific and EMS1/cortactin belong to a growing family of cytoskeletal SH3 proteins. Most proteins in this family, except for alpha-spectrin, contain a single SH3 domain at the C-terminus, and an F- actin binding domain (s) at the N-terminus. The main reason why EMS1 initially attracted great attention among molecular oncologists is the amplification and over-expression of EMS1 gene in mammary tumors. However, our recent study on HS1 suggests that EMS1 is a tumor suppressor rather than a proto-oncoprotein. First of all, full-length HS1 of 486 amino acids suppresses the malignant transformation caused by oncogenic Ras mutants such as v-Ha-Ras. Second, for its anti-oncog..