Extracellular matrix-regulated gene expression requires cooperation of SWI/SNF and transcription factors.
Extracellular cues play crucial roles in the transcriptional regulation of tissue-specific genes, but whether and how these signals lead to chromatin remodeling is not understood and subject to debate. Using chromatin immunoprecipitation assays and mammary-specific genes as models, we show here that extracellular matrix molecules and prolactin cooperate to induce histone acetylation and binding of transcription factors and the SWI/SNF complex to the beta- and gamma-casein promoters. Introduction of a dominant negative Brg1, an ATPase subunit of SWI/SNF complex, significantly reduced both beta- and gamma-casein expression, suggesting that SWI/SNF-dependent chromatin remodeling is required for transcription of mammary-specific genes. Chromatin immunoprecipitation analyses demonstrated that the ATPase activity of SWI/SNF is necessary for recruitment of RNA transcriptional machinery, but not for binding of transcription factors or for histone acetylation. Co-immunoprecipitation analyses showed that the SWI/SNF complex is associated with STAT5, CCAAT/enhancer-binding protein beta, and glucocorticoid receptor. Thus, extracellular matrix- and prolactin-regulated transcription of the mammary-specific casein genes requires the concerted action of chromatin remodeling enzymes and transcription factors.
Xu
Ren
R
Life Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA.
Spencer
Virginia A
VA
Bissell
Mina J
MJ
D000107:Acetylation; D000251:Adenosine Triphosphatases / Q000378:metabolism; D000818:Animals; D022782:CCAAT-Enhancer-Binding Protein-beta / Q000378:metabolism; D002364:Caseins / Q000096:biosynthesis; D002460:Cell Line; D042002:Chromatin Assembly and Disassembly / Q000502:physiology*; D047369:Chromatin Immunoprecipitation; D002868:Chromosomal Proteins, Non-Histone / Q000378:metabolism*; D004265:DNA Helicases / Q000235:genetics / Q000378:metabolism; D005109:Extracellular Matrix / Q000378:metabolism*; D005260:Female; D005799:Genes, Dominant / Q000235:genetics; D006657:Histones / Q000378:metabolism; D008321:Mammary Glands, Animal / Q000166:cytology / Q000378:metabolism*; D051379:Mice; D009154:Mutation; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism; D009928:Organ Specificity / Q000502:physiology; D011247:Pregnancy; D011388:Prolactin / Q000378:metabolism*; D011401:Promoter Regions, Genetic / Q000502:physiology; D011485:Protein Binding / Q000502:physiology; D011499:Protein Processing, Post-Translational / Q000502:physiology; D011965:Receptors, Glucocorticoid / Q000378:metabolism; D050799:STAT5 Transcription Factor / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D014158:Transcription, Genetic / Q000502:physiology*
D022782:CCAAT-Enhancer-Binding Protein-beta; D002364:Caseins; D002868:Chromosomal Proteins, Non-Histone; D006657:Histones; D009687:Nuclear Proteins; D011965:Receptors, Glucocorticoid; D050799:STAT5 Transcription Factor; C445179:SWI-SNF-B chromatin-remodeling complex; D014157:Transcription Factors; D011388:Prolactin; D000251:Adenosine Triphosphatases; C513194:Smarca4 protein, mouse; D004265:DNA Helicases