Involvement of histone deacetylation in MORC2-mediated down-regulation of carbonic anhydrase IX.
Carbonic anhydrase IX (CAIX) plays an important role in the growth and survival of tumor cells. MORC2 is a member of the MORC protein family. The MORC proteins contain a CW-type zinc finger domain and are predicted to have the function of regulating transcription, but no MORC2 target genes have been identified. Here we performed a DNA microarray hybridization and found CAIX mRNA to be down-regulated 8-fold when MORC2 was overexpressed. This result was further confirmed by northern and western blot analysis. Our results also showed that the protected region 4 (PR4) was important for the repression function of MORC2. Moreover, MORC2 decreased the acetylation level of histone H3 at the CAIX promoter. Meanwhile, trichostatin A (TSA) had an increasing effect on CAIX promoter activity. Among the six HDACs tested, histone deacetylase 4 (HDAC4) had a much more prominent effect on CAIX repression. ChIP and ChIP Re-IP assays showed that MORC2 and HDAC4 were assembled on the same region of the CAIX promoter. Importantly, we further confirmed that both proteins are simultaneously present in the PR4-binding complex. These results may contribute to understanding the molecular mechanisms of CAIX regulation.
Shao
Yangguang
Y
Department of Cell Biology, Key Laboratory of Cell Biology, Ministry of Public Health, and Key Laboratory of Medical Cell Biology, Ministry of Education, China Medical University, Shenyang 110001, China.
Li
Yan
Y
Zhang
Jian
J
Liu
Di
D
Liu
Furong
F
Zhao
Yue
Y
Shen
Tao
T
Li
Feng
F
D000951:Antigens, Neoplasm / Q000235:genetics* / Q000378:metabolism; D001665:Binding Sites; D000071231:Carbonic Anhydrase IX; D002256:Carbonic Anhydrases / Q000235:genetics* / Q000378:metabolism; D002460:Cell Line; D015536:Down-Regulation; D055785:Gene Knockdown Techniques; D006655:Histone Deacetylases / Q000378:metabolism*; D006801:Humans; D011401:Promoter Regions, Genetic; D012333:RNA, Messenger / Q000378:metabolism; D012097:Repressor Proteins / Q000378:metabolism*; D014157:Transcription Factors / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*
D000951:Antigens, Neoplasm; C549896:MORC2 protein, human; D012333:RNA, Messenger; D012097:Repressor Proteins; D014157:Transcription Factors; C400300:HDAC4 protein, human; D006655:Histone Deacetylases; C089226:CA9 protein, human; D000071231:Carbonic Anhydrase IX; D002256:Carbonic Anhydrases