BRG1 contains a conserved domain of the SWI2/SNF2 family necessary for normal mitotic growth and transcription.
Sequence-specific DNA binding activators of gene transcription may be assisted by SWI2 (SNF2), which contains a DNA-dependent ATPase domain. We have isolated a human complementary DNA encoding a 205K nuclear protein, BRG1, that contains extensive homology to SWI2 and Drosophila brahma. We report here that a SWI2/BRG1 chimera with the DNA-dependent ATPase domain replaced by corresponding human sequence restored normal mitotic growth and capacity for transcriptional activation to swi2- yeast cells. Point mutation of the conserved ATP binding site lysine abolished this complementation. This mutation in SWI2 exerted a dominant negative effect on transcription in yeast. A lysine to arginine substitution at the corresponding residue of BRG1 also generated a transcriptional dominant negative in human cells. BRG1 is exclusively nuclear and present in a high M(r) complex of about 2 x 10(6). These results show that the SWI2 family DNA-dependent ATPase domain has functional conservation between yeast and humans and suggest that a SWI/SNF protein complex is required for the activation of selective mammalian genes.
Khavari
P A
PA
Howard Hughes Medical Institute, Stanford University, California 94305.
Peterson
C L
CL
Tamkun
J W
JW
Mendel
D B
DB
Crabtree
G R
GR
D000251:Adenosine Triphosphatases / Q000235:genetics / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000378:metabolism; D000595:Amino Acid Sequence; D001483:Base Sequence; D004265:DNA Helicases; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D005816:Genetic Complementation Test; D006367:HeLa Cells; D006801:Humans; D008938:Mitosis; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism*; D009928:Organ Specificity; D017354:Point Mutation; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics; D029701:Saccharomyces cerevisiae Proteins; D017386:Sequence Homology, Amino Acid; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D014158:Transcription, Genetic
D004268:DNA-Binding Proteins; D009687:Nuclear Proteins; D011993:Recombinant Fusion Proteins; C499336:SMARCA1 protein, human; C084011:SMARCA2 protein, human; D029701:Saccharomyces cerevisiae Proteins; D014157:Transcription Factors; D000255:Adenosine Triphosphate; D000251:Adenosine Triphosphatases; C084108:SMARCA4 protein, human; C499333:SNF2 protein, S cerevisiae; D004265:DNA Helicases