Hematologic effects of inactivating the Ras processing enzyme Rce1.

Posttranslational processing of Ras proteins has attracted considerable interest as a potential target for anticancer drug discovery. Rce1 encodes an endoprotease that facilitates membrane targeting of Ras and other prenylated proteins by releasing the carboxyl-terminal 3 amino acids (ie, the -AAX of the CAAX motif). Homozygous Rce1 mutant embryos (Rce1(-/-)) die late in gestation.

MLL5, a homolog of Drosophila trithorax located within a segment of chromosome band 7q22 implicated in myeloid leukemia.

Proteins encoded by Polycomb and Trithorax-group (Pc-G and Trx-G) genes regulate developmental fates by maintaining or repressing HOX gene expression, respectively. In a search for candidate myeloid leukemia tumor suppressor genes from a approximately 2.5 Mb commonly-deleted segment within chromosome band 7q22, we identified a novel human Trithorax (Trx) family member named MLL5.