Synergistic activation of the human orphan nuclear receptor SHP gene promoter by basic helix-loop-helix protein E2A and orphan nuclear receptor SF-1.
The orphan nuclear receptor small heterodimer partner (SHP; NR0B2) is an unusual orphan nuclear receptor that lacks a conventional DNA-binding domain and acts as a modulator of transcriptional activities of a number of nuclear receptors. We have previously reported that the orphan nuclear receptor ERRgamma activates the SHP promoter. In this study, we have found that basic helix-loop-helix (bHLH) transcription factors, the E2A proteins (E47, E12 and E2/5), activated the human but not the mouse SHP promoter. In contrast, the tissue-specific E47 heterodimer partner BETA2 repressed the E47- mediated transactivation of the human SHP (hSHP) promoter. Using serial deletions and E-box mutant constructs of the hSHP promoter, we identified two E-boxes (E6 and E7) as E47-responsive E-boxes, which are not conserved in the mouse SHP promoter. Moreover, gel shift, chromatin immunoprecipitation (ChIP) and northern blot assays demonstrated that E47 directly binds to the hSHP promoter in vivo and in vitro and that Id proteins inhibited E47 binding to the hSHP promoter. Finally, we found that E47 and steroidogenic factor 1 (SF-1), a regulator of the SHP promoter, synergistically activate the human but not the mouse SHP promoter. Our findings suggest that the E2A proteins differentially regulate the human and mouse SHP promoters and cooperate with orphan nuclear receptor SF-1 for transcriptional activation of the hSHP promoter.
Kim
Han-Jong
HJ
Hormone Research Center, Chonnam National University, Kwangju, 500-757, Republic of Korea.
Kim
Joon-Young
JY
Park
Yun-Yong
YY
Choi
Hueng-Sik
HS
D000818:Animals; D001483:Base Sequence; D002460:Cell Line; D018257:Helix-Loop-Helix Motifs; D006801:Humans; D051379:Mice; D011401:Promoter Regions, Genetic / Q000235:genetics*; D011485:Protein Binding; D018160:Receptors, Cytoplasmic and Nuclear / Q000235:genetics* / Q000378:metabolism*; D012097:Repressor Proteins / Q000378:metabolism; D020218:Response Elements / Q000235:genetics; D017384:Sequence Deletion / Q000235:genetics; D013045:Species Specificity; D054339:Steroidogenic Factor 1; D015533:Transcriptional Activation
C515057:NR5A1 protein, human; D018160:Receptors, Cytoplasmic and Nuclear; D012097:Repressor Proteins; D054339:Steroidogenic Factor 1; C099713:nuclear receptor subfamily 0, group B, member 2; C515058:steroidogenic factor 1, mouse