Cloning and characterization of a corepressor and potential component of the nuclear hormone receptor repression complex.
Nuclear hormone receptors are potent repressors of transcription in the unliganded state. We describe here the cloning of a nuclear receptor corepressor that we call SUN-CoR (Small Unique Nuclear receptor CoRepressor), which shows no homology to previously described nuclear hormone receptor corepressors, N-CoR, or SMRT. SUN-CoR is a highly basic, 16-kDa nuclear protein that is expressed at high levels in adult tissues and is induced during adipocyte and myogenic differentiation. SUN-CoR potentiates transcriptional repression by thyroid hormone receptor and RevErb in vivo, represses transcription when fused to a heterologous DNA binding domain, and interacts with RevErb as well as with thyroid hormone receptor in vitro. SUN-CoR also interacts with N-CoR and SMRT in vitro and with endogenous N-CoR in cells. We conclude that SUN-CoR is a corepressor and may function as an additional component of the complex involved in transcriptional repression by unliganded and orphan nuclear hormone receptors.
Zamir
I
I
Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, University of Pennsylvania School of Medicine, Philadelphia, PA 19104, USA.
Dawson
J
J
Lavinsky
R M
RM
Glass
C K
CK
Rosenfeld
M G
MG
Lazar
M A
MA
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular; D051379:Mice; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000235:genetics* / Q000378:metabolism; D009928:Organ Specificity; D011956:Receptors, Cell Surface / Q000235:genetics / Q000378:metabolism*; D018160:Receptors, Cytoplasmic and Nuclear / Q000235:genetics / Q000378:metabolism*; D017421:Sequence Analysis; D015398:Signal Transduction
D009687:Nuclear Proteins; D011956:Receptors, Cell Surface; D018160:Receptors, Cytoplasmic and Nuclear