Multiple domains of the Receptor-Interacting Protein 140 contribute to transcription inhibition.
In this study, we have investigated the role of C-terminal binding proteins (CtBPs) and histone deacetylases (HDACs) in the repressive activity of the nuclear receptor cofactor Receptor-Interacting Protein 140 (RIP140). We have defined the interaction of both CtBP1 and CtBP2 with RIP140 and delineated two motifs (PIDLS and PINLS) differentially required for in vitro interaction. Using different approaches (titration of endogenous CtBPs, mutagenesis and transfection in CtBP knock-out cells), we find that recruitment of CtBPs only partially explains the negative regulation exerted by RIP140. We then demonstrate that RIP140 associates in vitro not only with class I HDACs but also with class II enzymes such as HDAC5. This interaction mainly involves the N-terminus of RIP140 (residues 27-199) and two domains of HDAC5. Moreover, the two proteins functionally interfere in transfection experiments, and confocal microscopy indicates that they co-localize in the nucleus. Interestingly, using the specific HDAC inhibitor trichostatin A, we show that HDAC activity is dispensable for active transrepression by RIP140. Finally, we demonstrate that the C-terminal region of RIP140 contains two additional silencing domains and confers strong active transrepression independently of HDAC activity and CtBPs. Altogether, these data indicate that transcriptional inhibition by the cofactor RIP140 involves complex mechanisms relying on multiple domains and partners.
Castet
Audrey
A
INSERM U540, Endocrinologie Moléculaire et Cellulaire des Cancers and Université de Montpellier I, 60 rue de Navacelles, 34090 Montpellier, France.
Boulahtouf
Abdelhay
A
Versini
Gwennaëlle
G
Bonnet
Sandrine
S
Augereau
Patrick
P
Vignon
Françoise
F
Khochbin
Saadi
S
Jalaguier
Stéphan
S
Cavaillès
Vincent
V
D048868:Adaptor Proteins, Signal Transducing; D000429:Alcohol Oxidoreductases; D000818:Animals; D002460:Cell Line; D004268:DNA-Binding Proteins / Q000235:genetics / Q000502:physiology; D004958:Estradiol / Q000494:pharmacology; D020868:Gene Silencing; D006655:Histone Deacetylases / Q000502:physiology; D006801:Humans; D051379:Mice; D018345:Mice, Knockout; D009687:Nuclear Proteins / Q000737:chemistry* / Q000378:metabolism*; D000078723:Nuclear Receptor Interacting Protein 1; D010750:Phosphoproteins / Q000235:genetics / Q000502:physiology; D017434:Protein Structure, Tertiary; D012097:Repressor Proteins / Q000737:chemistry* / Q000378:metabolism*; D014158:Transcription, Genetic
D048868:Adaptor Proteins, Signal Transducing; D004268:DNA-Binding Proteins; C000627127:NRIP1 protein, human; D009687:Nuclear Proteins; D000078723:Nuclear Receptor Interacting Protein 1; D010750:Phosphoproteins; D012097:Repressor Proteins; D004958:Estradiol; D000429:Alcohol Oxidoreductases; C096794:C-terminal binding protein; D006655:Histone Deacetylases