Orphan nuclear receptor Nur77 induces zinc finger protein GIOT-1 gene expression, and GIOT-1 acts as a novel corepressor of orphan nuclear receptor SF-1 via recruitment of HDAC2.
Kruppel-associated box (KRAB) domain-containing proteins consist of potential transcriptional repression modules. Previously, gonadotropin-inducible ovarian transcription factor-1 (GIOT-1) was identified as a novel KRAB-containing zinc finger protein and shown to have transcriptional repression activity. Here, we demonstrate that orphan nuclear receptor Nur77 regulates GIOT-1 gene expression in testicular Leydig cell lines and that GIOT-1 acts as a novel corepressor of the orphan nuclear receptor steroidogenic factor 1 (SF-1). Mutation analysis of the GIOT-1 promoter and overexpression analysis of dominant-negative Nur77 revealed that luteinizing hormone activates GIOT-1 gene expression through Nur77. Electrophoretic mobility shift and chromatin immunoprecipitation assays showed that Nur77 directly binds to the GIOT-1 promoter. GIOT-1 represses the SF-1 transactivation, and specific interaction between GIOT-1 and SF-1 was observed. We also demonstrate an interaction between GIOT-1 and histone deacetylase 2 (HDAC2). GIOT-1-mediated transrepression was recovered by down-regulation of HDAC2 expression with small interfering RNA of HDAC2. Knock down of the endogenous GIOT-1 results in significant enhancement of CYP17 expression in Leydig cells. In conclusion, this study of cross-talk between GIOT-1 and orphan nuclear receptors will provide new insights into the role of KRAB-containing zinc finger proteins in nuclear receptor action.
Song
Kwang-Hoon
KH
Hormone Research Center, School of Biological Sciences and Technology, Chonnam National University, Gwangju 500-757, Republic of Korea.
Park
Yun-Yong
YY
Kee
Hae Jin
HJ
Hong
Cheol Yi
CY
Lee
Yong-Soo
YS
Ahn
Seung-Won
SW
Kim
Hye-Jin
HJ
Lee
Keesook
K
Kook
Hyun
H
Lee
In-Kyu
IK
Choi
Hueng-Sik
HS
D000818:Animals; D001483:Base Sequence; D047369:Chromatin Immunoprecipitation; D004247:DNA; D004268:DNA-Binding Proteins / Q000502:physiology*; D024202:Electrophoretic Mobility Shift Assay; D005786:Gene Expression Regulation / Q000502:physiology*; D056464:Histone Deacetylase 2; D006655:Histone Deacetylases / Q000378:metabolism*; D018398:Homeodomain Proteins / Q000037:antagonists & inhibitors; D006801:Humans; D008297:Male; D051379:Mice; D008969:Molecular Sequence Data; D057105:Nuclear Receptor Subfamily 4, Group A, Member 1; D011401:Promoter Regions, Genetic; D034741:RNA, Small Interfering; D018160:Receptors, Cytoplasmic and Nuclear / Q000037:antagonists & inhibitors / Q000502:physiology*; D011987:Receptors, Steroid / Q000502:physiology*; D012097:Repressor Proteins / Q000378:metabolism*; D054339:Steroidogenic Factor 1; D013737:Testis / Q000166:cytology / Q000378:metabolism; D014157:Transcription Factors / Q000037:antagonists & inhibitors / Q000235:genetics* / Q000502:physiology*
D004268:DNA-Binding Proteins; D018398:Homeodomain Proteins; C539821:NR4A1 protein, human; C515057:NR5A1 protein, human; C539818:Nr4a1 protein, mouse; D057105:Nuclear Receptor Subfamily 4, Group A, Member 1; D034741:RNA, Small Interfering; D018160:Receptors, Cytoplasmic and Nuclear; D011987:Receptors, Steroid; D012097:Repressor Proteins; D054339:Steroidogenic Factor 1; D014157:Transcription Factors; C447181:ZNF461 protein, human; C515058:steroidogenic factor 1, mouse; D004247:DNA; C533424:Hdac2 protein, mouse; D056464:Histone Deacetylase 2; D006655:Histone Deacetylases