CR6-interacting factor 1 interacts with orphan nuclear receptor Nur77 and inhibits its transactivation.
CR6-interacting factor 1 (CRIF1) was recently identified as a nuclear protein that interacts with the Gadd45 (growth arrest and DNA damage inducible 45) family of proteins and participates in the regulation of the G1/S phase of the cell cycle. However, the nuclear action of CRIF1 is largely unknown. In this study, we demonstrate that CRIF1 acts as a novel coregulator of transactivation of the orphan nuclear receptor Nur77. Both in vitro and in vivo studies show that CRIF1 interacts with Nur77 via the Nur77 AB domain and that it dramatically inhibits the AB domain-mediated transactivation of Nur77. Transient transfection assays demonstrate that CRIF1 inhibits steroid receptor coactivator-2-mediated Nur77 transactivation, and silencing of endogenous CRIF1 by small interfering RNA relieves this repression. CRIF1 possesses intrinsic repressor activities that are not affected by the histone deacetylase inhibitor Trichostatin A. In addition, overexpression of CRIF1 inhibits TSH/protein kinase A-induced Nur-responsive element promoter activity. CRIF1 inhibited Nur77-dependent induction of E2F1 promoter activity, mRNA expression, and Nur77-mediated G1/S progression in cell cycle. These results suggest that CRIF1 acts as a repressor of the orphan nuclear receptor Nur77 by inhibiting AB domain-mediated transcriptional activity.
Laboratory of Endocrine Cell Biology, Department of Internal Medicine, Chungnam National University College of Medicine, 640 Daesadong Chungku Daejeon 301-721, Korea.
Ki Cheol
KC
Park
Kwang-Hoon
KH
Song
Hyo Kyun
HK
Chung
Ho
H
Kim
Dong Wook
DW
Kim
Jung Hun
JH
Song
Eun Suk
ES
Hwang
Hye Sook
HS
Jung
Su-Hyeon
SH
Park
Insoo
I
Bae
In Kyu
IK
Lee
Hueng-Sik
HS
Choi
Minho
M
Shong
D000818:Animals; D002453:Cell Cycle; D018797:Cell Cycle Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D002478:Cells, Cultured; D017868:Cyclic AMP-Dependent Protein Kinases / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D015292:Glycoprotein Hormones, alpha Subunit / Q000494:pharmacology; D006801:Humans; D051379:Mice; D009154:Mutation / Q000235:genetics; D057105:Nuclear Receptor Subfamily 4, Group A, Member 1; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D034741:RNA, Small Interfering / Q000235:genetics / Q000378:metabolism; D018160:Receptors, Cytoplasmic and Nuclear / Q000235:genetics / Q000378:metabolism*; D011987:Receptors, Steroid / Q000235:genetics / Q000378:metabolism*; D020218:Response Elements / Q000235:genetics; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D015533:Transcriptional Activation / Q000235:genetics*
D018797:Cell Cycle Proteins; D004268:DNA-Binding Proteins; D015292:Glycoprotein Hormones, alpha Subunit; C539821:NR4A1 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; D014157:Transcription Factors; D017868:Cyclic AMP-Dependent Protein Kinases