The Tale of Two Domains

Abstract

Very little is known about SET-and MYND-containing protein 2 (SMYD2), a member of the SMYD protein family. However, the interest in better understanding the roles of SMYD2 has grown because of recent reports indicating that SMYD2 methylates p53 and histone H3. In this study, we present a combined proteomics and genomics study of SMYD2 designed to elucidate its molecular roles. We report the cytosolic and nuclear interactome of SMYD2 using a combination of immunoprecipitation coupled with high throughput MS, chromatin immunoprecipitation coupled with high throughput MS, and co-immunoprecipitation methods. In particular, we report that SMYD2 interacted with HSP90␣ independently of the SET and MYND domains, with EBP41L3 through the MYND domain, and with p53 through the SET domain. We demonstrated that the interaction of SMYD2 with HSP90␣ enhances SMYD2 histone methyltransferase activity and specificity for histone H3 at lysine 4 (H3K4) in vitro. Interestingly histone H3K36 methyltransferase activity was independent of its interaction with HSP90␣ similar to LSD1 dependence on the androgen receptor. We also showed that the SET domain is required for the methylation at H3K4. We demonstrated using a modified chromatin immunoprecipitation protocol that the SMYD2 gain of function leads to an increase in H3K4 methylation in vivo, whereas no observable levels of H3K36 were detected. We also report that the SMYD2 gain of function was correlated with the upregulation of 37 and down-regulation of four genes, the majority of which are involved in the cell cycle, chromatin remodeling, and transcriptional regulation. TACC2 is one of the genes up-regulated as a result of SMYD2 gain of function. Up-regulation of TACC2 by SMYD2 occurred as a result of SMYD2 binding to the TACC2 promoter where it methylates H3K4. Furthermore the combination of the SMYD2 interactome with the gene expression data suggests that some of the genes regulated by SMYD2 are closely associated with SMYD2-interacting proteins. Molecular & Cellular Proteomics 7:560 -572, 2008.The mapping of protein-protein interaction helps us understand the function of proteins. In recent years, our group (1) and others (2, 3) have performed protein interaction experiments for large sets of human proteins. Our approach for the mapping of protein-protein interactions is based on immunoprecipitation coupled with high throughput MS (IP-HTMS). 1The SMYD protein family consists of five proteins (SMYD1-5) that are not fully characterized and are grouped based on the presence of two conserved domains (MYND and SET domains). The MYND domain is a zinc finger motif that is involved in protein-protein interaction. It is named after Myeloid, Nervy, and DEAF-1, which are the three most characterized proteins that contain the MYND domain (4). The SET domain is an evolutionarily conserved sequence motif consisting of 130 -140 amino acids. Its name is derived from the three proteins in which it was initially characterized: Su (var) 3-9, Enhancer-of-zeste, and Trithorax (5, 6). These enzymes a...

Post-transcriptional gene silencing, transcriptional gene silencing and human immunodeficiency virus

“…However, there is some indirect evidence of a similar mechanism in mammalian somatic cells when transduced with lentiviral vectors. In fact, reduced expression of the introduced transgene was observed during differentiation in a murine model and silencing was found to be the result of DNA methylation of the promoter of the lentivirus driven August 12, 2015|Volume 4|Issue 3| WJV|www.wjgnet.com 229 [229] , SET7 (mono) [230] , MLL [231] , SMYD2 [232] LSD1 (mono and di) [233] , JARID1A/ KDM5A JARID1B/ KDM5B (di and tri) [234] CHD1 [235] , RAG2 [236] , TAF3 [237] , BPTF [238] , BHC80 [239] , ING FAMILY [240] , PYGO2 [241] [ [244] SIRT6 [245] BRD4 [246] [247]…”

“…Transcription elongation NSD1, NSD2 [263] , SET2 [264] , SMYD2 [232] , MMSET [265] ASH1 [266] , JHDM1 [267] , JHDM1A/KDM2A, JHDM1B/KDM2B [268] ISW1B [269] H4K20 me1 me2 me3 (non-genic regions, centromeric heterochromatin, satellite sequences, long terminal repeats Transcritional silencing, heterochromatin, repression of proinflammatory genes PR-SET7/SET8 [270] SUV420H1, SUV420H2 [274] SUV420H2 [274] , SMYD5 [275] PHF8 [271] PHF2 [275] PHF2 [275] L3MBTL1 [272] PHF20 [276] , L3MBTL1 [277] NcoR [275] [ gene [158] . Furthermore, it is well known that a considerable amount of integrated vectors become silent [159] , and this effect seems to be dependent on the promoter chosen to drive the ectopic expression of the gene [160,161] .…”

Crystal Structure of Cardiac-specific Histone Methyltransferase SmyD1 Reveals Unusual Active Site Architecture

“…In vitro studies have shown that SmyD1, -2, and -3 specifically methylate histone H3 lysine 4 (3,7,8), suggesting that they may function as a transcriptional activator. However, several reports indicated that SmyD1 functions as a transcriptional repressor in cardiomyocyte maturation and heartbeat rhythm regulation and its repressive activity is dependent on the recruitment of class I histone deacetylase (2,6).…”

“…SmyD1 belongs to a subfamily of SET containing proteins that consists of five members (SmyD1-5) (7). In vitro studies have shown that SmyD1, -2, and -3 specifically methylate histone H3 lysine 4 (3,7,8), suggesting that they may function as a transcriptional activator.…”

TACC2 (transforming acidic coiled‐coil protein 2) in breast carcinoma as a potent prognostic predictor associated with cell proliferation

“…Therefore, TACC2 does not necessarily involve in AR signaling and other factors can be important in the regulation of TACC2 expression in the breast carcinoma, different from the prostate carcinoma. For instance, it has been reported that TACC2 was up‐regulated by SMYD2 (SET‐ and MYND‐containing protein 2) gain of function, and it occurred as a result of SMYD2 binding to the TACC2 promoter where it methylated histone H3 at lysine 4 (H3K4) 24. Further examinations are needed to clarify molecular regulatory mechanisms of TACC2 expression in breast carcinoma.…”