RACK-1, a receptor for activated C kinase, interacts with the transcription factor NFAT and represses its transactivation.
To isolate and characterize a novel protein that interacts with nuclear factor of activated T cells (NFAT) and potentially regulates its activity, we screened a Jurkat cDNA library by using the NFAT regulatory domain as bait in the yeast two-hybrid system. RACK-1, a receptor for activated protein kinase C and a homologue of the G-protein beta subunit, was identified as a NFAT-binding protein. Mammalian two hybrid tests in CV-1 cells and a coimmunoprecipitation assay confirmed protein-protein interaction between NFAT and RACK-1. In addition, overexpression of RACK-1 specifically suppressed transcriptional activation derived by NFAT, but not by NF-kappaB. These results demonstrate RACK-1 as a potent negative modulator of NFAT activation and suggest a novel mechanism in NFAT regulation.
Han
Juhyun
J
Department of Bioscience and Biotechnology, Hankuk University of Foreign Studies, Yongin 449-791, Korea.
Kim
Minjung
M
Oum
Ji-Hyun
JH
Myung
Heejoon
H
Lee
Seong-Wook
SW
Jeong
Sunjoo
S
Sharma
Surendra
S
Park
Jungchan
J
D000818:Animals; D015153:Blotting, Western; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D015536:Down-Regulation / Q000502:physiology; D015971:Gene Expression Regulation, Enzymologic; D015723:Gene Library; D000882:Haplorhini; D006801:Humans; D019169:Jurkat Cells; D007668:Kidney / Q000378:metabolism; D008156:Luciferases / Q000378:metabolism; D016328:NF-kappa B / Q000378:metabolism / Q000494:pharmacology; D050778:NFATC Transcription Factors; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism; D010957:Plasmids / Q000378:metabolism; D011233:Precipitin Tests; D011401:Promoter Regions, Genetic; D011485:Protein Binding / Q000235:genetics; D011493:Protein Kinase C / Q000378:metabolism; D000075370:Receptors for Activated C Kinase; D011956:Receptors, Cell Surface / Q000235:genetics / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000235:genetics; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D014158:Transcription, Genetic; D015533:Transcriptional Activation / Q000235:genetics*; D014162:Transfection; D020798:Two-Hybrid System Techniques
D004268:DNA-Binding Proteins; D016328:NF-kappa B; D050778:NFATC Transcription Factors; D009687:Nuclear Proteins; D000075370:Receptors for Activated C Kinase; D011956:Receptors, Cell Surface; D014157:Transcription Factors; D008156:Luciferases; D011493:Protein Kinase C