Novel RING finger proteins, Air1p and Air2p, interact with Hmt1p and inhibit the arginine methylation of Npl3p.
Heterogeneous nuclear ribonucleoproteins (hnRNPs) are involved in the mRNA processing and export and are post-translationally modified by methylation at arginine residues in their arginine-glycine-rich (RGG) domains. We screened the factors that can interact with the RGG domain of Npl3p only in the presence of Hmt1p with the two-hybrid system in Saccharomyces cerevisiae. An isolated clone, YIL079, encodes a novel RING finger protein that was not directly bound to Npl3p but associated with the N terminus of Hmt1p. Thus, we designated the gene product Air1p (arginine methyltransferase-interacting RING finger protein). Air1p inhibited the Hmt1p-mediated methylation of Npl3p in vitro. Overexpression of Air1p repressed the Hmt1p-dependent growth of cells. Since homology searches indicate that the YDL175 gene product has significant identity (45%) with Air1p, we designated the gene AIR2. Air2p also has a RING finger domain and was bound to Hmt1p. Although single disruption of either gene gave no effect on the cell growth, cells lacking Air1p and Air2p grew at an extremely slow rate with accumulated poly(A)(+) RNA in the nucleus. Thus, Air1p and Air2p may affect mRNA transport by regulating the arginine methylation state of heterogeneous nuclear ribonucleoproteins.
Inoue
K
K
Department of Functional Genomics, Medical Research Institute, Tokyo, Japan.
Mizuno
T
T
Wada
K
K
Hagiwara
M
M
D018528:ATP-Binding Cassette Transporters / Q000737:chemistry / Q000378:metabolism*; D048868:Adaptor Proteins, Signal Transducing; D000595:Amino Acid Sequence; D001120:Arginine; D001483:Base Sequence; D002352:Carrier Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D003001:Cloning, Molecular; D017931:DNA Primers; D005656:Fungal Proteins / Q000737:chemistry / Q000378:metabolism*; D005838:Genotype; D008745:Methylation; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D009687:Nuclear Proteins / Q000737:chemistry / Q000378:metabolism*; D011484:Protein-Arginine N-Methyltransferases; D016601:RNA-Binding Proteins; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism; D012097:Repressor Proteins; D012441:Saccharomyces cerevisiae / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D016335:Zinc Fingers
D018528:ATP-Binding Cassette Transporters; D048868:Adaptor Proteins, Signal Transducing; C415824:Air1 protein, S cerevisiae; C415825:Air2 protein, S cerevisiae; D002352:Carrier Proteins; D017931:DNA Primers; D005656:Fungal Proteins; C077734:NPL3 protein, S cerevisiae; D009687:Nuclear Proteins; D016601:RNA-Binding Proteins; D011994:Recombinant Proteins; D012097:Repressor Proteins; D029701:Saccharomyces cerevisiae Proteins; D001120:Arginine; C475182:HMT1 protein, S cerevisiae; D011484:Protein-Arginine N-Methyltransferases