Molecular cloning of xSRC-3, a novel transcription coactivator from Xenopus, that is related to AIB1, p/CIP, and TIF2.
Nuclear receptors regulate transcription by binding to specific DNA response elements of target genes. Herein, we report the molecular cloning and characterization of a novel Xenopus cDNA encoding a transcription coactivator xSRC-3 by using retinoid X receptor (RXR) as a bait in the yeast two-hybrid screening. It belongs to a growing coactivator family that includes a steroid receptor coactivator amplified in breast cancer (AIB1), p300/ CREB-binding protein (CBP)-interacting protein (p/ CIP), and transcriptional intermediate factor 2 (TIF2). It also interacts with a series of nuclear receptors including retinoic acid receptor (RAR), thyroid hormone receptor (TR), and orphan nuclear receptors [hepatocyte nuclear receptor 4 (HNF4) and constitutive androstane receptor (CAR)]. However, it does not interact with small heterodimer partner (SHP), an orphan nuclear receptor known to antagonize ligand-dependent transactivation of other nuclear receptors. In CV-1 cells, cotransfection of xSRC-3 differentially stimulates ligand-induced transactivation of RXR, TR, and RAR in a dose-dependent manner. Interestingly, xSRC-3 is highly expressed in adult liver and early stages of oocyte development, suggesting that studies of xSRC-3 may lead to better understanding of the roles nuclear receptors play in oocyte development as well as liver-specific gene expression.
Kim
H J
HJ
College of Pharmacy, Chonnam National University, Kwangju, South Korea.
Lee
S K
SK
Na
S Y
SY
Choi
H S
HS
Lee
J W
JW
D000123:Acetyltransferases; D017398:Alternative Splicing; D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D002467:Cell Nucleus / Q000378:metabolism; D003001:Cloning, Molecular; D005260:Female; D015870:Gene Expression; D051548:Histone Acetyltransferases; D006801:Humans; D008969:Molecular Sequence Data; D016296:Mutagenesis; D056920:Nuclear Receptor Coactivator 1; D051958:Nuclear Receptor Coactivator 2; D056921:Nuclear Receptor Coactivator 3; D015513:Oncogene Proteins; D018168:Receptors, Retinoic Acid / Q000378:metabolism; D011988:Receptors, Thyroid Hormone / Q000378:metabolism; D011993:Recombinant Fusion Proteins; D047488:Retinoid X Receptors; D012441:Saccharomyces cerevisiae / Q000235:genetics; D017385:Sequence Homology; D015534:Trans-Activators / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D014157:Transcription Factors / Q000737:chemistry / Q000378:metabolism; D015533:Transcriptional Activation; D014981:Xenopus; D029867:Xenopus Proteins
C498001:NCOA2 protein, human; C114568:NCOA3 protein, Xenopus; D051958:Nuclear Receptor Coactivator 2; D015513:Oncogene Proteins; D018168:Receptors, Retinoic Acid; D011988:Receptors, Thyroid Hormone; D011993:Recombinant Fusion Proteins; D047488:Retinoid X Receptors; D015534:Trans-Activators; D014157:Transcription Factors; D029867:Xenopus Proteins; D000123:Acetyltransferases; D051548:Histone Acetyltransferases; C538859:NCOA1 protein, human; C538866:NCOA3 protein, human; D056920:Nuclear Receptor Coactivator 1; D056921:Nuclear Receptor Coactivator 3