Generation of the dominant-negative mutant of hArpNbeta: a component of human SWI/SNF chromatin remodeling complex.
hArpNbeta, an actin-related protein located within the nucleus, is a subunit of the human SWI/SNF chromatin remodeling complex. hArpNbeta has been proposed to regulate the assembly and activity of the hSWI/SNF complex. Sequence comparisons of the potential ArpN homologs with beta-actin showed that the ArpNs have the divergent subdomains Ib and IIb in addition to the unique N-terminal short insert, MS(G/A)-(V/L)YGG. Since the proposed function of hArpNbeta requires more than two distinct but concurrently operating surfaces, we examined whether the disruption of one operating surface of hArpNbeta results in dominant-negative phenotype. When overexpressed in HeLa or 293T cells, the subdomain Ib or IIb hybrids, in which the subdomain Ib or IIb of hArpNbeta was replaced with that of beta-actin, respectively, showed no effect on cell survival. On the other hand, the overexpression of the N-terminal deletion mutant of hArpNbeta resulted in cell death probably through apoptotic process. These results indicate that the proper function of hArpNbeta is essential for cell survival in human cells. Furthermore, they suggests the possibility that the N-terminal short sequence is indispensable for the chromatin remodeling activity or the assembly of the hSWI/SNF complex after the binding of hArpNbeta with functionally essential partner proteins.
Choi
E Y
EY
Department of Bioscience and Biotechnology, Hankuk University of Foreign Studies, Yongin-Shi Kyongki-do, 449-791, Korea.
Park
J A
JA
Sung
Y H
YH
Kwon
H
H
D000199:Actins / Q000737:chemistry / Q000235:genetics; D000595:Amino Acid Sequence; D000818:Animals; D017209:Apoptosis / Q000502:physiology; D002460:Cell Line; D002467:Cell Nucleus / Q000378:metabolism; D002470:Cell Survival; D002868:Chromosomal Proteins, Non-Histone / Q000737:chemistry* / Q000235:genetics* / Q000378:metabolism; D004268:DNA-Binding Proteins; D006801:Humans; D046911:Macromolecular Substances; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009154:Mutation; D009687:Nuclear Proteins / Q000737:chemistry* / Q000235:genetics* / Q000378:metabolism; D020033:Protein Isoforms / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D017434:Protein Structure, Tertiary; D016415:Sequence Alignment; D014162:Transfection
C116160:ACTL6A protein, human; D000199:Actins; D002868:Chromosomal Proteins, Non-Histone; D004268:DNA-Binding Proteins; D046911:Macromolecular Substances; D009687:Nuclear Proteins; D020033:Protein Isoforms