Proteomic analyses of the SMYD family interactomes identify HSP90 as a novel target for SMYD2

Abstract

The SMYD (SET and MYND domain) family of lysine methyltransferases (KMTs) plays pivotal roles in various cellular processes, including gene expression regulation and DNA damage response. Initially identified as genuine histone methyltransferases, specific members of this family have recently been shown to methylate non-histone proteins such as p53, VEGFR, and the retinoblastoma tumor suppressor (pRb). To gain further functional insights into this family of KMTs, we generated the protein interaction network for three different human SMYD proteins (SMYD2, SMYD3, and SMYD5). Characterization of each SMYD protein network revealed that they associate with both shared and unique sets of proteins. Among those, we found that HSP90 and several of its co-chaperones interact specifically with the tetratrico peptide repeat (TPR)-containing SMYD2 and SMYD3. Moreover, using proteomic and biochemical techniques, we provide evidence that SMYD2 methylates K209 and K615 on HSP90 nucleotide-binding and dimerization domains, respectively. In addition, we found that each methylation site displays unique reactivity in regard to the presence of HSP90 co-chaperones, pH, and demethylation by the lysine amine oxidase LSD1, suggesting that alternative mechanisms control HSP90 methylation by SMYD2. Altogether, this study highlights the ability of SMYD proteins to form unique protein complexes that may underlie their various biological functions and the SMYD2-mediated methylation of the key molecular chaperone HSP90.

Genomic incompatibilities in the diploid and tetraploid offspring of the goldfish × common carp cross

“…There were 617 of these terms shared by all offspring, and the terms of "mutagenesis site" and "disease mutation" had high gene counts (P < 3.6E−22). In all offspring, chimeric genes were involved directly in spindle assembly [e.g., casein kinase (CSNK)], spliceosome (e.g., TRA2, PRPF8), RNA polymerase (e.g., RPB, RPC), or chromatin modification (e.g., SMYD, JHDM1D_E_F) (23)(24)(25)(26)(27)(28). Chimeric genes also participated in the activities of mitogen-activated protein kinase (MAPK) [e.g., Fig.…”

KMTase Set7/9 is a critical regulator of E2F1 activity upon genotoxic stress

“…1,56 However, recently published reports suggest that methylation of non-histone targets is also instrumental in these processes. Several KMTases, besides Set7/9, were found to methylate important cell-cycle regulators (Rb, 57 p53, 58,59 heat shock protein 90 (HSP90) 60,61 ). In this study, we show that Set7/9 has a critical role in regulation of cell cycle by promoting E2F1-dependent transcription of the CCNE1 gene upon DNA damage.…”

H3K36 Methyltransferases as Cancer Drug Targets: Rationale and Perspectives for Inhibitor Development

“…However, inhibition or knockdown of SMYD2 does not change global H3K36 or H3K4 mono-, di-or tri-methylation, and most of SMYD2 is found in the cytoplasm, suggesting SMYD2's activity on chromatin may be minimal [108]. Indeed, SMYD2 methylates many nonhistone substrates including p53, RB, HSP90, estrogen receptor α and PARP1 [109][110][111][112][113], conveying wide-ranging effects on transcriptional regulation, protein homeostasis, apoptosis and the DNA damage response.…”

“…However, inhibition or knockdown of SMYD2 does not change global H3K36 or H3K4 mono-, di-or tri-methylation, and most of SMYD2 is found in the cytoplasm, suggesting SMYD2's activity on chromatin may be minimal [108]. Indeed, SMYD2 methylates many nonhistone substrates including p53, RB, HSP90, estrogen receptor α and PARP1 [109][110][111][112][113], conveying wide-ranging effects on transcriptional regulation, protein homeostasis, apoptosis and the DNA damage response.The SETMAR gene evolved from fusion of a SET domain to a transposase domain [114]. As described in the 'DNA repair' section above, the SETMAR protein has been linked to cancer via its role in DNA repair, which requires SETMAR's KMTase activity [33].…”