Species-specific variation of RPA-interacting protein (RIP) splice isoforms

Korea Basic Science Institute, Gwangju Center, Gwangju 500-757, Korea.
BMB reports (Impact Factor: 2.6). 02/2009; 42(1):22-7. DOI: 10.5483/BMBRep.2009.42.1.022
Source: PubMed


Replication Protein A (RPA) is a single stranded DNA-binding protein involved in DNA metabolic activities such as replication, repair, and recombination. RPA-Interacting Protein alpha (RIPalpha) was originally identified as a nuclear transporter of RPA in Xenopus. The human RIPalpha gene encodes several splice isoforms, of which hRIPalpha and hRIPbeta are the major translation products in vivo. However, limited information is available about the alternative splicing of RIPalpha in eukaryotes, apart from that in humans. In this study, we examined the alternative splicing of RIPalpha in the Drosophila, Xenopus, and mouse system. We showed that the number of splice isoforms of RIPalpha was species-specific, and displayed a tendency to increase in higher eukaryotes. Moreover, a mouse ortholog of hRIPbeta, mRIPbeta2, was not SUMOylated, in contrast to hRIPbeta. Based on these results, we suggest that the RIPalpha gene gains more splice isoforms and additional modifications after molecular evolution. [BMB reports 2009; 42(1): 22-27].

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Available from: Seung-Hoon Lee, Mar 04, 2014
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    • "Initially, xenopus RIPa gene (xRIPa) was cloned, and subsequently hRIPa, the human orthologue of xRIPa, was identified. Reverse transcription-polymerase chain reaction (RT-PCR) analyses revealed that the hRIPa gene has many splice isoforms, and hRIPa and its splice isoform, hRIPb, are expressed; however, a microscopy study showed their subcellular localizations are distinctive [12] [13]. hRI- Pa transports RPA into the nucleus by shuttling between the cytoplasm and nucleus while hRIPb is localized in promyelocytic leukemia (PML) nuclear bodies [12]. "
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    ABSTRACT: Replication protein A (RPA) is a eukaryotic single-stranded DNA binding protein that is essential for DNA replication, repair, and recombination, and human RPA interacting protein α (hRIPα) is the nuclear transporter of RPA. Here, we report the regulatory role of hRIPα protein in cell proliferation. Western blot analysis revealed that the level of hRIPα was frequently elevated in cervical tumors tissues and hRIPα knockdown by siRNA inhibited cellular proliferation through deregulation of the cell cycle. In addition, overexpression of hRIPα resulted in increased clonogenicity. These results indicate that hRIPα is involved in cell proliferation through regulation of RPA transport.
    FEBS letters 09/2012; 586(20):3753-60. DOI:10.1016/j.febslet.2012.09.010 · 3.17 Impact Factor