Q9H7B4

SET and MYND domain-containing 3 (SMYD3), a 428-amino acid protein, is a member of an RNA polymerase complex and plays a role in transcriptional regulation. SMYD3 methylates Lys-4 of Histone H3, a specific tag for epigenetic transcriptional activation. The SMYD3 protein contains an N-terminal MYND-type zinc finger domain, followed by a SET domain, which shows methyltransferase activity. The presence of the heatshock protein HSP 90A greatly enhances SMYD3′s methyltransferase activity. SMYD3 is expressed in testis and skeletal muscles and is over-expressed in a majority of colorectal carcinomas (CRCs), hepatocellular carcinomas (HCCs) as well as breast carcinomas (BCs). Inhibition of SMYD3 is a potential chemotherapeutic strategy.