SMYD3 (D2Q4V) Rabbit mAb #12859

SET and MYND domain containing protein 3 (SMYD3) is a member of the SET domain-containing family of protein methyltransferases and is localized to both the nucleus and cytoplasm (1-3). Several histone substrates have been identified for SMYD3; however, the data is controversial. In one study, SMYD3 has been shown to methylate histone H3 Lys4 (both di- and tri-methylation) and interact with RNA polymerase II to activate transcription (1). A second study has shown that SMYD3 preferentially methylates histone H4 Lys20 and interacts with nuclear receptor corepressor complex (NCOR) to repress transcription (2). A third study has shown that SMYD3 preferentially methylates histone H4 Lys5 (mono-, di-, and tri-methylation) (3). In addition, SMYD3 has been shown to methylate the endothelial growth factor receptor 1 (VEGFR1) on Lys831 and stimulate its kinase activity (4). Regardless of the preferred protein substrates, it is clear that SMYD3 functions as an oncogene. Research studies have shown SMYD3 is highly over-expressed in liver, breast, and rectal carcinomas. Over-expression of SMYD3 in multiple cell lines enhances proliferation, adhesion, and migration, while reduced expression results in significant suppression of cell growth (1,5-10). In addition, multiple cancer cell lines express both full length SMYD3 and a cleaved form of SMYD3 lacking the N-terminal 34 amino acids, and the cleaved form shows increased methyltransferase activity toward histone H3 (11).