Effects of Ser2 and Tyr6 mutants of BAF53 on cell growth and p53-dependent transcription.
BAF53 is an actin-related protein that shuttles between nucleus and cytoplasm. In the nucleus, it constitutes an integral component of many chromatin-modifying complexes such as the SWI/SNF, TIP60, TRRAP, and TIP48/49 complexes. BAF53 is essential for growth, but its function remains elusive. BAF53 homologues from yeast to humans have a conserved N-terminal motif, MS_(G/A)(G/A)_(V/L)YGG, which is unique to these proteins. Previously we showed that over-expression of an N-terminal deletion mutant of BAF53 (BAF53_deltaN) reduced the viability of HEK293 and HeLa cells. When we replaced the serine 2 and tyrosine 6 of this N-terminal motif with alanine, over-expression of the alanine-replaced BAF53 strongly impaired the growth of HEK293 cells whereas replacement with aspartate/glutamate had no effect. The alanine-replaced BAF53 mutants also stimulated p53-dependent transcription, in which the SWI/SNF and TRRAP complexes are involved. Our results demonstrate that serine 2 and tyrosine 6 play important roles in BAF53 activity.
Lee
Jung Hwa
JH
Department of Bioscience and Biotechnology, Hankuk University of Foreign Studies, Yongin 449-791, Korea.
Lee
Ji Yeon
JY
Chang
Seok Hoon
SH
Kang
Mi Jin
MJ
Kwon
Hyockman
H
D000199:Actins / Q000235:genetics* / Q000378:metabolism; D048868:Adaptor Proteins, Signal Transducing; D000409:Alanine / Q000737:chemistry / Q000235:genetics; D049109:Cell Proliferation; D002478:Cells, Cultured; D002843:Chromatin / Q000378:metabolism*; D002868:Chromosomal Proteins, Non-Histone / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000235:genetics* / Q000378:metabolism; D006801:Humans; D007668:Kidney / Q000378:metabolism; D009154:Mutation / Q000235:genetics*; D009687:Nuclear Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D011401:Promoter Regions, Genetic / Q000235:genetics*; D012694:Serine / Q000737:chemistry / Q000235:genetics; D014157:Transcription Factors / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D014158:Transcription, Genetic; D016159:Tumor Suppressor Protein p53 / Q000235:genetics / Q000378:metabolism*; D014443:Tyrosine / Q000737:chemistry / Q000235:genetics
C116160:ACTL6A protein, human; D000199:Actins; D048868:Adaptor Proteins, Signal Transducing; D002843:Chromatin; D002868:Chromosomal Proteins, Non-Histone; D004268:DNA-Binding Proteins; D009687:Nuclear Proteins; C445179:SWI-SNF-B chromatin-remodeling complex; D014157:Transcription Factors; D016159:Tumor Suppressor Protein p53; C113829:transformation-transcription domain-associated protein; D014443:Tyrosine; D012694:Serine; D000409:Alanine