A novel human nucleolar protein, Nop132, binds to the G proteins, RRAG A/C/D.
RRAG A (Rag A)/Gtr1p is a member of the Ras-like small G protein family that genetically interacts with RCC1, a guanine nucleotide exchange factor for RanGTPase. RRAG A/Gtr1p forms a heterodimer with other G proteins, RRAG C and RRAG D/Gtr2p, in a nucleotide-independent manner. To further elucidate the function of RRAG A/Gtr1p, we isolated a protein that interacts with RRAG A. This protein is a novel nucleolar protein, Nop132. Nop132 is associated with the GTP form, but not the GDP form, of RRAG A, suggesting that RRAG A might regulate Nop132 function. Nop132 is also associated with RRAG C and RRAG D. The Nop132 amino acid sequence is similar to the Saccharomyces cerevisiae nucleolar Nop8p, which is associated with Gtr1p, Gtr2p, and Nip7p. Nop132 also interacts with human Nip7 and is colocalized with RRAG A, RRAG C, and Nip7. RNA interference knockdown of Nop132 inhibited cell growth of HeLa cells.
Sekiguchi
Takeshi
T
Department of Molecular Biology, Graduate School of Medical Science, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan. sekigu@molbiol.med.kyushu-u.ac.jp
Todaka
Yuko
Y
Wang
Yonggang
Y
Hirose
Eiji
E
Nakashima
Nobutaka
N
Nishimoto
Takeharu
T
D000595:Amino Acid Sequence; D000818:Animals; D016367:Baculoviridae / Q000235:genetics; D001665:Binding Sites; D002352:Carrier Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D002455:Cell Division; D002460:Cell Line; D004247:DNA / Q000378:metabolism; D015870:Gene Expression; D005822:Genetic Vectors; D005982:Glutathione Transferase / Q000235:genetics; D006367:HeLa Cells; D006801:Humans; D016350:Leucine Zippers; D008969:Molecular Sequence Data; D020559:Monomeric GTP-Binding Proteins / Q000737:chemistry / Q000378:metabolism*; D009687:Nuclear Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D012313:RNA / Q000378:metabolism; D034741:RNA, Small Interfering / Q000235:genetics; D011993:Recombinant Fusion Proteins; D012269:Ribosomal Proteins / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000737:chemistry; D029701:Saccharomyces cerevisiae Proteins / Q000378:metabolism; D018411:Spodoptera / Q000378:metabolism; D014162:Transfection; D020798:Two-Hybrid System Techniques
D002352:Carrier Proteins; C107936:NIP7 protein, S cerevisiae; C484521:NOL8 protein, human; D009687:Nuclear Proteins; D034741:RNA, Small Interfering; C430722:RRAGC protein, human; C430723:RRAGD protein, human; D011993:Recombinant Fusion Proteins; D012269:Ribosomal Proteins; D029701:Saccharomyces cerevisiae Proteins; D012313:RNA; D004247:DNA; D005982:Glutathione Transferase; C484342:RRAGA protein, human; D020559:Monomeric GTP-Binding Proteins