SMYD3

SMYD3 is a SET and MYND domain-containing lysine methyltransferase that catalyzes the methylation of histone and non-histone substrates^[1][2]. Mechanistically, SMYD3 coordinates transcriptional regulation by forming complexes with proteins such as SMAD3 and RACK1, thereby promoting target gene expression involved in cell proliferation and migration^[3][4][5]. In disease models, SMYD3 overexpression is associated with enhanced epithelial-mesenchymal transition (EMT), tumor invasion, and metastasis in breast, colorectal, and liver cancers^[3][4][5][6]. Compared with related isoforms, including SMYD2 and SMYD5, SMYD3 demonstrates distinct substrate specificity and structural features, such as a TPR-containing C-terminal domain that forms a narrow substrate-binding pocket critical for enzymatic activity^[7][2]. Structural studies also indicate that the DNA-binding MYND domain further modulates its catalytic function, enhancing histone methylation^[2]. For experimental applications, pharmacological inhibitors such as BCI121 effectively block SMYD3-mediated chromatin association and reduce malignant phenotypes in cancer cell lines and zebrafish xenograft models^[3][5]. Additionally, SMYD3 influences skeletal and cardiac muscle differentiation by targeting myogenic transcription factors, highlighting its utility in developmental and stem cell research^[8][9]. These combined functional and structural insights establish SMYD3 as a distinct epigenetic regulator with both oncogenic and developmental relevance^[1][2].