Swapping function of two chromatin remodeling complexes.
SWI/SNF- and ISWI-based complexes have distinct yet overlapping chromatin-remodeling activities in vitro and perform different roles in vivo. This leads to the hypothesis that the distinct remodeling functions of these complexes are specifically required for distinct biological tasks. By creating and characterizing chimeric proteins of BRG1 and SNF2h, the motor proteins of human SWI/SNF- and ISWI-based complexes, respectively, we found that a region that includes the ATPase domain specifies the outcome of the remodeling reaction in vitro. A chimeric protein based on BRG1 but containing the SNF2h ATPase domain formed an intact SWI/SNF complex that remodeled like SNF2h. This altered-function complex was active for remodeling and could stimulate expression from some, but not all, SWI/SNF responsive promoters in vivo. Thus, we were able to separate domains of BRG1 responsible for function from those responsible for SWI/SNF complex formation and demonstrate that remodeling functions are not interchangeable in vivo.
Fan
Hua-Ying
HY
Department of Molecular Biology, Massachusetts General Hospital, Boston, Massachusetts 02114, USA.
Trotter
Kevin W
KW
Archer
Trevor K
TK
Kingston
Robert E
RE
D000251:Adenosine Triphosphatases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D000310:Adrenal Gland Neoplasms / Q000235:genetics / Q000378:metabolism; D002843:Chromatin / Q000378:metabolism*; D042002:Chromatin Assembly and Disassembly; D002868:Chromosomal Proteins, Non-Histone / Q000235:genetics / Q000378:metabolism*; D004265:DNA Helicases; D006801:Humans; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism*; D009707:Nucleosomes / Q000502:physiology; D011401:Promoter Regions, Genetic / Q000235:genetics; D017434:Protein Structure, Tertiary; D011965:Receptors, Glucocorticoid / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D014158:Transcription, Genetic; D015533:Transcriptional Activation; D014407:Tumor Cells, Cultured; D016335:Zinc Fingers
D002843:Chromatin; D002868:Chromosomal Proteins, Non-Histone; D009687:Nuclear Proteins; D009707:Nucleosomes; D011965:Receptors, Glucocorticoid; D011993:Recombinant Fusion Proteins; D014157:Transcription Factors; D000251:Adenosine Triphosphatases; C084108:SMARCA4 protein, human; C409462:SMARCA5 protein, human; D004265:DNA Helicases