Search Results

You are looking at 71 - 80 of 1,550 items for :

  • transcription x
  • Refine by access: All content x
Clear All
Magda A Meester-Smoor Department of Pathology, Erasmus MC-Josephine Nefkens Institute, PO Box 2040, 3000 CA Rotterdam, The Netherlands
Department of Genetics and Tumor Cell Biology, St Jude Children’s Research Hospital, 332 North Lauderdale, Memphis, Tennessee 38105, USA

Search for other papers by Magda A Meester-Smoor in
Google Scholar
PubMed
Close
,
Anco C Molijn Department of Pathology, Erasmus MC-Josephine Nefkens Institute, PO Box 2040, 3000 CA Rotterdam, The Netherlands
Department of Genetics and Tumor Cell Biology, St Jude Children’s Research Hospital, 332 North Lauderdale, Memphis, Tennessee 38105, USA

Search for other papers by Anco C Molijn in
Google Scholar
PubMed
Close
,
Yixian Zhao Department of Pathology, Erasmus MC-Josephine Nefkens Institute, PO Box 2040, 3000 CA Rotterdam, The Netherlands
Department of Genetics and Tumor Cell Biology, St Jude Children’s Research Hospital, 332 North Lauderdale, Memphis, Tennessee 38105, USA

Search for other papers by Yixian Zhao in
Google Scholar
PubMed
Close
,
Nicole A Groen Department of Pathology, Erasmus MC-Josephine Nefkens Institute, PO Box 2040, 3000 CA Rotterdam, The Netherlands
Department of Genetics and Tumor Cell Biology, St Jude Children’s Research Hospital, 332 North Lauderdale, Memphis, Tennessee 38105, USA

Search for other papers by Nicole A Groen in
Google Scholar
PubMed
Close
,
Cora A H Groffen Department of Pathology, Erasmus MC-Josephine Nefkens Institute, PO Box 2040, 3000 CA Rotterdam, The Netherlands
Department of Genetics and Tumor Cell Biology, St Jude Children’s Research Hospital, 332 North Lauderdale, Memphis, Tennessee 38105, USA

Search for other papers by Cora A H Groffen in
Google Scholar
PubMed
Close
,
Merel Boogaard Department of Pathology, Erasmus MC-Josephine Nefkens Institute, PO Box 2040, 3000 CA Rotterdam, The Netherlands
Department of Genetics and Tumor Cell Biology, St Jude Children’s Research Hospital, 332 North Lauderdale, Memphis, Tennessee 38105, USA

Search for other papers by Merel Boogaard in
Google Scholar
PubMed
Close
,
Diny van Dalsum-Verbiest Department of Pathology, Erasmus MC-Josephine Nefkens Institute, PO Box 2040, 3000 CA Rotterdam, The Netherlands
Department of Genetics and Tumor Cell Biology, St Jude Children’s Research Hospital, 332 North Lauderdale, Memphis, Tennessee 38105, USA

Search for other papers by Diny van Dalsum-Verbiest in
Google Scholar
PubMed
Close
,
Gerard C Grosveld Department of Pathology, Erasmus MC-Josephine Nefkens Institute, PO Box 2040, 3000 CA Rotterdam, The Netherlands
Department of Genetics and Tumor Cell Biology, St Jude Children’s Research Hospital, 332 North Lauderdale, Memphis, Tennessee 38105, USA

Search for other papers by Gerard C Grosveld in
Google Scholar
PubMed
Close
, and
Ellen C Zwarthoff Department of Pathology, Erasmus MC-Josephine Nefkens Institute, PO Box 2040, 3000 CA Rotterdam, The Netherlands
Department of Genetics and Tumor Cell Biology, St Jude Children’s Research Hospital, 332 North Lauderdale, Memphis, Tennessee 38105, USA

Search for other papers by Ellen C Zwarthoff in
Google Scholar
PubMed
Close

kidney physiology ( Schneider et al. 2002 ). Expression of IGFBP5 is stimulated by IGF-1 through the phosphatidylinositol-3 kinase pathway ( Kiepe et al. 2005 ). Transcription factors that have been shown to affect the IGFBP5 promoter are the

Free access
Yujiro Yamanaka Department of Physiology, Hokkaido University Graduate school of Medicine, Sapporo, Japan
Laboratory of Life and Health Science, Hokkaido University Graduate school of Education, Sapporo, Japan
Research and Education Center for Brain Science, Hokkaido University, Sapporo, Japan

Search for other papers by Yujiro Yamanaka in
Google Scholar
PubMed
Close
,
Yoshiko Yamada Department of Chronomedicine, Hokkaido University Graduate school of Medicine, Sapporo, Japan

Search for other papers by Yoshiko Yamada in
Google Scholar
PubMed
Close
,
Ken-ichi Honma Department of Chronomedicine, Hokkaido University Graduate school of Medicine, Sapporo, Japan

Search for other papers by Ken-ichi Honma in
Google Scholar
PubMed
Close
, and
Sato Honma Research and Education Center for Brain Science, Hokkaido University, Sapporo, Japan
Department of Chronomedicine, Hokkaido University Graduate school of Medicine, Sapporo, Japan

Search for other papers by Sato Honma in
Google Scholar
PubMed
Close

demonstrated an importance of this neural pathway not only for the nocturnal melatonin synthesis ( Deguchi & Axelrod 1972 ) but also for day/night changes in transcription of thousands of genes ( Hartley et al. 2015 ). Activation of the β1-adrenergic receptor

Free access
A Al Kahtane
Search for other papers by A Al Kahtane in
Google Scholar
PubMed
Close
,
Y Chaiseha
Search for other papers by Y Chaiseha in
Google Scholar
PubMed
Close
, and
M El Halawani
Search for other papers by M El Halawani in
Google Scholar
PubMed
Close

It is well documented that prolactin (PRL) release and PRL gene expression in birds are controlled by the tonic stimulation of hypothalamic vasoactive intestinal peptide (VIP). However, there is good evidence that dopamine (DA) exerts both stimulatory (at the hypothalamic level) and inhibitory (at the pituitary level) effects on PRL secretion. The interactions between VIP and DA in the regulation of PRL gene transcription are not known. This study was designed to examine the effects of a D(2) DA receptor agonist (D(2)AG; R(-)-propylnorapomorphine HCl) on basal and VIP-stimulated PRL gene transcription rate, PRL mRNA steady-state levels, PRL mRNA stability and PRL release from cultured turkey anterior pituitary cells. The D(2)AG (10(-)(10) M) completely inhibited the stimulatory effect of VIP (10(-)(7) M) upon nascent PRL mRNA as determined utilizing a nuclear run-on transcription assay. To examine further the effect of the D(2)AG on PRL mRNA post-transcriptional events, anterior pituitary cells were treated with different concentrations of D(2)AG (10(-)(12)-10(-)(4) M). Semi-quantitative RT-PCR and RIA were performed to determine the levels of PRL mRNA and PRL content in the medium respectively. The results show that D(2)AG inhibited VIP-stimulated PRL mRNA steady-state levels as well as basal and VIP-stimulated PRL release, effects which were diminished by the D(2) DA receptor antagonist, S(-)-eticlopride HCl (10(-)(10) M). Actinomycin D (5 microg/ml), an inhibitor of mRNA synthesis, was used to assess the effect of D(2)AG on PRL mRNA stability in response to VIP. The stimulatory effect of VIP on PRL mRNA stability was completely negated by the D(2)AG (from a half-life of 53.0+/-2.3 h in VIP-treated cells to 25.5+/-1.6 h in D(2)AG+VIP-treated cells, P<or=0.05). These results support the hypothesis that VIP and DA play a major role in the regulation of PRL gene expression in avian species, at both the transcriptional and post-transcriptional levels. In addition, these findings suggest that the DAergic system inhibits PRL release and synthesis by antagonizing VIP at the pituitary level via D(2) DA receptors.

Free access
G Aguilera
Search for other papers by G Aguilera in
Google Scholar
PubMed
Close
,
S Volpi
Search for other papers by S Volpi in
Google Scholar
PubMed
Close
, and
C Rabadan-Diehl
Search for other papers by C Rabadan-Diehl in
Google Scholar
PubMed
Close

The number of V1b vasopressin receptors (V1bR) in the anterior pituitary plays an important role during adaptation of the hypothalamic-pituitary-adrenal axis to stress in rats. Regulation of V1bR expression involves transcriptional and translational mechanisms. One of the elements mediating transcriptional activation of the rat V1bR gene is a long stretch of GAGA repeats (GAGA box) in the promoter located near the transcription start point capable of binding a protein complex of 127 kDa present in pituitary nuclear extracts. There is a lack of correlation between changes in V1bR mRNA and the number of VP binding sites, suggesting that V1bR expression depends on the efficiency of V1b R mRNA translation into protein. Two mechanisms by which the 5' untranslated region (5'-UTR) of the rat V1bR mRNA can mediate either inhibition or activation of V1bR mRNA translation have been identified. First, upstream open reading frames (ORF) present in the 5'-UTR repress translation of the major ORF encoding the V1b receptor, and secondly, an internal ribosome entry site (IRES) activates V1bR translation. Stimulation of IRES activity through protein kinase C-mediated pathways results in V1bR mRNA translation increasing V1bR protein levels. The existence of multiple loci of regulation for the V1bR at transcriptional and translational levels provides a mechanism to facilitate plasticity of regulation of the number of pituitary vasopressin receptors according to physiological demand.

Free access
Cynthia S Ritter Renal Division, Washington University Medical School, Box 8126, 660 S. Euclid, St Louis, Missouri 63110, USA

Search for other papers by Cynthia S Ritter in
Google Scholar
PubMed
Close
,
Sangeeta Pande Renal Division, Washington University Medical School, Box 8126, 660 S. Euclid, St Louis, Missouri 63110, USA

Search for other papers by Sangeeta Pande in
Google Scholar
PubMed
Close
,
Irina Krits Renal Division, Washington University Medical School, Box 8126, 660 S. Euclid, St Louis, Missouri 63110, USA

Search for other papers by Irina Krits in
Google Scholar
PubMed
Close
,
Eduardo Slatopolsky Renal Division, Washington University Medical School, Box 8126, 660 S. Euclid, St Louis, Missouri 63110, USA

Search for other papers by Eduardo Slatopolsky in
Google Scholar
PubMed
Close
, and
Alex J Brown Renal Division, Washington University Medical School, Box 8126, 660 S. Euclid, St Louis, Missouri 63110, USA

Search for other papers by Alex J Brown in
Google Scholar
PubMed
Close

broadened our understanding of the mechanism of PTH mRNA decay by Ca. Using in vitro degradation assays, Moallem et al . (1998) showed that an increase in PTH mRNA levels in hypocalcemic rats was due to post-transcriptional stabilization of PTH mRNA

Free access
Edward T Bagu Centre de recherche du Centre hospitalier de l'Université de Montréal (CRCHUM) and Institut du cancer de Montréal, Department of Medicine, Université de Montréal, Montréal, Québec, Canada

Search for other papers by Edward T Bagu in
Google Scholar
PubMed
Close
and
Manuela M Santos Centre de recherche du Centre hospitalier de l'Université de Montréal (CRCHUM) and Institut du cancer de Montréal, Department of Medicine, Université de Montréal, Montréal, Québec, Canada
Centre de recherche du Centre hospitalier de l'Université de Montréal (CRCHUM) and Institut du cancer de Montréal, Department of Medicine, Université de Montréal, Montréal, Québec, Canada

Search for other papers by Manuela M Santos in
Google Scholar
PubMed
Close

. 2010 ). Increases in the concentration of iron and inflammation upregulate the transcription of hepcidin, while iron deficiency and hypoxia downregulate it ( Nicolas et al . 2002 ). At present, it is unclear as to what the molecular mechanisms involved

Free access
A Cote-Vélez Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, AP 510-3, Cuernavaca, Mor. 62250, México

Search for other papers by A Cote-Vélez in
Google Scholar
PubMed
Close
,
L Pérez-Martínez Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, AP 510-3, Cuernavaca, Mor. 62250, México

Search for other papers by L Pérez-Martínez in
Google Scholar
PubMed
Close
,
M Y Díaz-Gallardo Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, AP 510-3, Cuernavaca, Mor. 62250, México

Search for other papers by M Y Díaz-Gallardo in
Google Scholar
PubMed
Close
,
C Pérez-Monter Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, AP 510-3, Cuernavaca, Mor. 62250, México

Search for other papers by C Pérez-Monter in
Google Scholar
PubMed
Close
,
A Carreón-Rodríguez Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, AP 510-3, Cuernavaca, Mor. 62250, México

Search for other papers by A Carreón-Rodríguez in
Google Scholar
PubMed
Close
,
J-L Charli Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, AP 510-3, Cuernavaca, Mor. 62250, México

Search for other papers by J-L Charli in
Google Scholar
PubMed
Close
, and
P Joseph-Bravo Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, AP 510-3, Cuernavaca, Mor. 62250, México

Search for other papers by P Joseph-Bravo in
Google Scholar
PubMed
Close

that activate TRH release from the median eminence ( Arancibia et al. 1983 , de Greef et al. 1987 , Rondel et al. 1988 ). At the transcriptional level, the negative feedback of thyroid hormones is well characterized ( Segerson et al

Free access
Nobuko Kimura
Search for other papers by Nobuko Kimura in
Google Scholar
PubMed
Close
,
Nobuko Takamatsu
Search for other papers by Nobuko Takamatsu in
Google Scholar
PubMed
Close
,
Yoshio Yaoita Tokyo Metropolitan Institute for Neuroscience, Division of Embryology and Genetics, Department of Pathology, Tokyo Metropolitan Institute of Gerontology, Tokyo Metropolitan Organization for Medical Research, 2-6 Musashidai, Fuchu, Tokyo 183-8526, Japan

Search for other papers by Yoshio Yaoita in
Google Scholar
PubMed
Close
,
R Yoshiyuki Osamura Tokyo Metropolitan Institute for Neuroscience, Division of Embryology and Genetics, Department of Pathology, Tokyo Metropolitan Institute of Gerontology, Tokyo Metropolitan Organization for Medical Research, 2-6 Musashidai, Fuchu, Tokyo 183-8526, Japan

Search for other papers by R Yoshiyuki Osamura in
Google Scholar
PubMed
Close
, and
Narimichi Kimura Tokyo Metropolitan Institute for Neuroscience, Division of Embryology and Genetics, Department of Pathology, Tokyo Metropolitan Institute of Gerontology, Tokyo Metropolitan Organization for Medical Research, 2-6 Musashidai, Fuchu, Tokyo 183-8526, Japan

Search for other papers by Narimichi Kimura in
Google Scholar
PubMed
Close

pathological importance, molecular mechanism underlying transcriptional regulation of the human sst2 gene remains unclear. Previous reports showed that an initiator element, SSTR2inr, exists in proximal upstream of the coding region and forms a core promoter

Free access
Masanori Ito Departments of, Geriatric Medicine, Anti-Aging Medicine, Obstetrics and Gynaecology, Department of Integrated Women's Health, Research Center for Genomic Medicine, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655, Japan
Departments of, Geriatric Medicine, Anti-Aging Medicine, Obstetrics and Gynaecology, Department of Integrated Women's Health, Research Center for Genomic Medicine, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655, Japan
Departments of, Geriatric Medicine, Anti-Aging Medicine, Obstetrics and Gynaecology, Department of Integrated Women's Health, Research Center for Genomic Medicine, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655, Japan

Search for other papers by Masanori Ito in
Google Scholar
PubMed
Close
,
Tomohiko Urano Departments of, Geriatric Medicine, Anti-Aging Medicine, Obstetrics and Gynaecology, Department of Integrated Women's Health, Research Center for Genomic Medicine, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655, Japan
Departments of, Geriatric Medicine, Anti-Aging Medicine, Obstetrics and Gynaecology, Department of Integrated Women's Health, Research Center for Genomic Medicine, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655, Japan

Search for other papers by Tomohiko Urano in
Google Scholar
PubMed
Close
,
Hisahiko Hiroi Departments of, Geriatric Medicine, Anti-Aging Medicine, Obstetrics and Gynaecology, Department of Integrated Women's Health, Research Center for Genomic Medicine, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655, Japan

Search for other papers by Hisahiko Hiroi in
Google Scholar
PubMed
Close
,
Mikio Momoeda Departments of, Geriatric Medicine, Anti-Aging Medicine, Obstetrics and Gynaecology, Department of Integrated Women's Health, Research Center for Genomic Medicine, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655, Japan
Departments of, Geriatric Medicine, Anti-Aging Medicine, Obstetrics and Gynaecology, Department of Integrated Women's Health, Research Center for Genomic Medicine, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655, Japan

Search for other papers by Mikio Momoeda in
Google Scholar
PubMed
Close
,
Mayuko Saito Departments of, Geriatric Medicine, Anti-Aging Medicine, Obstetrics and Gynaecology, Department of Integrated Women's Health, Research Center for Genomic Medicine, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655, Japan

Search for other papers by Mayuko Saito in
Google Scholar
PubMed
Close
,
Yumi Hosokawa Departments of, Geriatric Medicine, Anti-Aging Medicine, Obstetrics and Gynaecology, Department of Integrated Women's Health, Research Center for Genomic Medicine, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655, Japan

Search for other papers by Yumi Hosokawa in
Google Scholar
PubMed
Close
,
Ryo Tsutsumi Departments of, Geriatric Medicine, Anti-Aging Medicine, Obstetrics and Gynaecology, Department of Integrated Women's Health, Research Center for Genomic Medicine, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655, Japan

Search for other papers by Ryo Tsutsumi in
Google Scholar
PubMed
Close
,
Fumiko Zenri Departments of, Geriatric Medicine, Anti-Aging Medicine, Obstetrics and Gynaecology, Department of Integrated Women's Health, Research Center for Genomic Medicine, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655, Japan

Search for other papers by Fumiko Zenri in
Google Scholar
PubMed
Close
,
Minako Koizumi Departments of, Geriatric Medicine, Anti-Aging Medicine, Obstetrics and Gynaecology, Department of Integrated Women's Health, Research Center for Genomic Medicine, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655, Japan

Search for other papers by Minako Koizumi in
Google Scholar
PubMed
Close
,
Hanako Nakae Departments of, Geriatric Medicine, Anti-Aging Medicine, Obstetrics and Gynaecology, Department of Integrated Women's Health, Research Center for Genomic Medicine, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655, Japan

Search for other papers by Hanako Nakae in
Google Scholar
PubMed
Close
,
Kuniko Horie-Inoue Departments of, Geriatric Medicine, Anti-Aging Medicine, Obstetrics and Gynaecology, Department of Integrated Women's Health, Research Center for Genomic Medicine, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655, Japan

Search for other papers by Kuniko Horie-Inoue in
Google Scholar
PubMed
Close
,
Tomoyuki Fujii Departments of, Geriatric Medicine, Anti-Aging Medicine, Obstetrics and Gynaecology, Department of Integrated Women's Health, Research Center for Genomic Medicine, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655, Japan

Search for other papers by Tomoyuki Fujii in
Google Scholar
PubMed
Close
,
Tetsu Yano Departments of, Geriatric Medicine, Anti-Aging Medicine, Obstetrics and Gynaecology, Department of Integrated Women's Health, Research Center for Genomic Medicine, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655, Japan

Search for other papers by Tetsu Yano in
Google Scholar
PubMed
Close
,
Shiro Kozuma Departments of, Geriatric Medicine, Anti-Aging Medicine, Obstetrics and Gynaecology, Department of Integrated Women's Health, Research Center for Genomic Medicine, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655, Japan

Search for other papers by Shiro Kozuma in
Google Scholar
PubMed
Close
,
Satoshi Inoue Departments of, Geriatric Medicine, Anti-Aging Medicine, Obstetrics and Gynaecology, Department of Integrated Women's Health, Research Center for Genomic Medicine, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655, Japan
Departments of, Geriatric Medicine, Anti-Aging Medicine, Obstetrics and Gynaecology, Department of Integrated Women's Health, Research Center for Genomic Medicine, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655, Japan
Departments of, Geriatric Medicine, Anti-Aging Medicine, Obstetrics and Gynaecology, Department of Integrated Women's Health, Research Center for Genomic Medicine, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655, Japan

Search for other papers by Satoshi Inoue in
Google Scholar
PubMed
Close
, and
Yuji Taketani Departments of, Geriatric Medicine, Anti-Aging Medicine, Obstetrics and Gynaecology, Department of Integrated Women's Health, Research Center for Genomic Medicine, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655, Japan

Search for other papers by Yuji Taketani in
Google Scholar
PubMed
Close

plays an important role in implantation, and PR is a member of the nuclear receptor superfamily that regulates the transcription of an array of responsive genes ( Mangelsdorf et al . 1995 ). PR is detected as two distinct proteins, namely, PR-A and PR

Free access
S Kobayashi
Search for other papers by S Kobayashi in
Google Scholar
PubMed
Close
,
H Shibata
Search for other papers by H Shibata in
Google Scholar
PubMed
Close
,
I Kurihara
Search for other papers by I Kurihara in
Google Scholar
PubMed
Close
,
K Yokota
Search for other papers by K Yokota in
Google Scholar
PubMed
Close
,
N Suda
Search for other papers by N Suda in
Google Scholar
PubMed
Close
,
I Saito
Search for other papers by I Saito in
Google Scholar
PubMed
Close
, and
T Saruta
Search for other papers by T Saruta in
Google Scholar
PubMed
Close

Chicken ovalbumin upstream promoter-transcription factors (COUP-TFs) are orphan receptors involved in regulation of neurogenesis and organogenesis. COUP-TF family members are generally considered to be transcriptional repressors and several mechanisms have been proposed to underlie this activity. To explore novel transcriptional coregulators for COUP-TFs, we used the COUP-TFI as bait in a yeast two-hybrid screen of an adrenocortical adenoma cDNA library. We have identified Ubc9, a class E2 conjugating enzyme of small ubiquitin-related modifier (SUMO)-1 as a COUP-TFI corepressor. Ubc9 interacts with COUP-TFI in yeast and in glutathione S-transferase pulldown and coimmunoprecipitation assays. Fluorescence imaging studies show that both Ubc9 and COUP-TFI are colocalized in the nuclei of transfected COS-1 cells. The C-terminal region of Ubc9 encoding amino acids 59-158 interacts with the C-terminus of COUP-TFI encoding amino acids 383-403, in which transcriptional repression domains are located. Mammalian one-hybrid assays utilizing a variety of Ubc9 fragments fused to Gal4 DNA-binding domain show that a Ubc9 fragment encoding amino acids 1-89 contains autonomous transferrable repression domain. Transfection of Ubc9 into COS-1 cells markedly enhances transcriptional repression by Gal4 DNA-binding domain-fused to COUP-TFI(155-423), but not by Gal4-COUP-TFI(155-388) which lacks a repressor domain. Coexpression of a C-terminal deletion mutant of Ubc9(1-58), which fails to interact with COUP-TFI, but retains a transcriptional repression domain, has no effect on Gal4-COUP-TFI-mediated repression activity. These findings indicate that interaction of Ubc9 with COUP-TFI is crucial for the corepressor function of Ubc9. Overexpression of Ubc9 similarly enhances COUP-TFI-dependent repression of the promoter activity of the bovine CYP17 gene encoding steroid 17alpha-hydroxylase. In addition, the C93S mutant of Ubc9, which abrogates SUMO-1 conjugation activity, continues to function as a COUP-TFI corepressor. Our studies indicate that Ubc9 functions as a novel COUP-TFI corepressor, the function of which is distinct from its SUMO-1 conjugating enzyme activity.

Free access