IL-2 production in developing Th1 cells is regulated by heterodimerization of RelA and T-bet and requires T-bet serine residue 508.
Interleukin (IL)-2 is the predominant cytokine that is produced by naive Th cells in a primary response. It is required for proliferation and differentiation of Th precursor cells into effector cells. Initial high-level IL-2 production is followed by its decline, and the concomitant induction of cytokines that are typical of the differentiated state. Although the factors that are responsible for the early induction of IL-2 are well defined, the mechanisms that are responsible for its down-regulation in later stages of Th development have not been studied as much. Previous work from our laboratory revealed a repressor function for the T-box transcription factor, T-bet, in IL-2 gene transcription. Here, we report that T-bet(S508) is required for the optimal repression of IL-2 production in developing Th1 cells. Phosphorylation of T-bet(S508) by casein kinase I and glycogen synthase kinase-3 kinases accompanies T-bet's interaction with the RelA nuclear factor-kappaB transcription factor. Heterodimerization of T-bet and RelA interferes with the binding of RelA to the IL-2 promoter, and hence, transcriptional activation of the IL-2 gene by RelA.
Hwang
Eun Sook
ES
Division of Molecular Life Sciences and College of Pharmacy, Ewha Womans University, Seoul, Korea.
Hong
Jeong-Ho
JH
Glimcher
Laurie H
LH
D000818:Animals; D001483:Base Sequence; D047389:Casein Kinase I / Q000502:physiology; D002454:Cell Differentiation / Q000502:physiology; D045744:Cell Line, Tumor; D002999:Clone Cells; D019281:Dimerization; D005786:Gene Expression Regulation / Q000502:physiology; D038362:Glycogen Synthase Kinase 3 / Q000502:physiology; D007376:Interleukin-2 / Q000037:antagonists & inhibitors / Q000096:biosynthesis* / Q000235:genetics; D051379:Mice; D008810:Mice, Inbred C57BL; D008969:Molecular Sequence Data; D010766:Phosphorylation; D011401:Promoter Regions, Genetic; D012333:RNA, Messenger / Q000378:metabolism; D012694:Serine / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D020825:T-Box Domain Proteins; D018417:Th1 Cells / Q000166:cytology / Q000378:metabolism*; D051996:Transcription Factor RelA / Q000378:metabolism* / Q000502:physiology; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism* / Q000502:physiology; D000098815:T-bet Transcription Factor
D007376:Interleukin-2; D012333:RNA, Messenger; C498144:Rela protein, mouse; D020825:T-Box Domain Proteins; D000098815:T-bet Transcription Factor; D051996:Transcription Factor RelA; D014157:Transcription Factors; D012694:Serine; D047389:Casein Kinase I; D038362:Glycogen Synthase Kinase 3