Sumoylation of the novel protein hRIP{beta} is involved in replication protein A deposition in PML nuclear bodies.
Replication protein A (RPA) is a single-stranded-DNA-binding protein composed of three subunits with molecular masses of 70, 32, and 14 kDa. The protein is involved in multiple processes of eukaryotic DNA metabolism, including DNA replication, repair, and recombination. In Xenopus, Xenopus RPA-interacting protein alpha has been identified as a carrier molecule of RPA into the nucleus. In this study, human RPA-interacting protein alpha (hRIPalpha) and five novel splice isoforms (named hRIPalpha, hRIPbeta, hRIPgamma, hRIPdelta1, hRIPdelta2, and hRIPdelta3 according to the lengths of their encoding peptides) were cloned. Among hRIP isoforms, hRIPalpha and hRIPbeta were found to be the major splice isoforms and to show different subcellular localizations. While hRIPalpha localized to the cytoplasm, hRIPbeta was found in the PML nuclear body. Modification of hRIPbeta by sumoylation was found to be required for localization to the PML nuclear body. The results of the present work demonstrate that hRIPbeta transports RPA into the PML nuclear body and releases RPA upon UV irradiation. hRIPbeta thus plays an important role in RPA deposition in PML nuclear bodies and thereby supplements RPA for DNA metabolism.
Park
Junsoo
J
Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejon 305-701, South Korea.
Seo
Taegun
T
Kim
Hakzoo
H
Choe
Joonho
J
D021581:Active Transport, Cell Nucleus; D017398:Alternative Splicing; D000595:Amino Acid Sequence; D002352:Carrier Proteins / Q000032:analysis / Q000235:genetics / Q000378:metabolism*; D002453:Cell Cycle / Q000528:radiation effects; D002467:Cell Nucleus / Q000737:chemistry / Q000378:metabolism*; D002478:Cells, Cultured; D003001:Cloning, Molecular; D003593:Cytoplasm / Q000737:chemistry / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000032:analysis / Q000378:metabolism*; D006801:Humans; D008969:Molecular Sequence Data; D009363:Neoplasm Proteins / Q000378:metabolism; D019913:Nuclear Localization Signals / Q000235:genetics / Q000378:metabolism; D009687:Nuclear Proteins / Q000378:metabolism; D000071156:Promyelocytic Leukemia Protein; D020033:Protein Isoforms / Q000032:analysis / Q000235:genetics / Q000378:metabolism; D051716:Replication Protein A; D016196:S Phase / Q000528:radiation effects; D014157:Transcription Factors / Q000378:metabolism; D025521:Tumor Suppressor Proteins / Q000378:metabolism; D014466:Ultraviolet Rays
D002352:Carrier Proteins; D004268:DNA-Binding Proteins; D009363:Neoplasm Proteins; D019913:Nuclear Localization Signals; D009687:Nuclear Proteins; D000071156:Promyelocytic Leukemia Protein; D020033:Protein Isoforms; C504742:RPA-interacting protein alpha, human; C497167:RPA1 protein, human; D051716:Replication Protein A; D014157:Transcription Factors; D025521:Tumor Suppressor Proteins; C070576:PML protein, human