title: Rtp1p is a karyopherin-like protein required for RNA polymerase II biogenesis.
abstract: The assembly and nuclear transport of RNA polymerase II (RNA pol II) are processes that require the participation of many auxiliary factors. In a yeast genetic screen, we identified a previously uncharacterized gene, YMR185w (renamed RTP1), which encodes a protein required for the nuclear import of RNA pol II. Using protein affinity purification coupled to mass spectrometry, we identified interactions between Rtp1p and members of the R2TP complex. Rtp1p also interacts, to a different extent, with several RNA pol II subunits. The pattern of interactions is compatible with a role for Rtp1p as an assembly factor that participates in the formation of the Rpb2/Rpb3 subassembly complex and its binding to the Rpb1p-containing subcomplex. Besides, Rtp1p has a molecular architecture characteristic of karyopherins, composed of HEAT repeats, and is able to interact with phenylalanine-glycine-containing nucleoporins. Our results define Rtp1p as a new component of the RNA pol II biogenesis machinery that plays roles in subunit assembly and likely in transport through the nuclear pore complex.
authors: Departamento de Bioquímica y Biología Molecular, Facultad de Biología, Universitat de València, Burjassot, Spain.
authors: Natalia
authors: N
authors: Gómez-Navarro
authors: Lorena
authors: L
authors: Peiró-Chova
authors: Susana
authors: S
authors: Rodriguez-Navarro
authors: Julio
authors: J
authors: Polaina
authors: Francisco
authors: F
authors: Estruch
mesh_terms: D021581:Active Transport, Cell Nucleus; D002352:Carrier Proteins / Q000032:analysis / Q000378:metabolism; D017353:Gene Deletion; D015966:Gene Expression Regulation, Fungal; D028884:Karyopherins / Q000032:analysis / Q000235:genetics / Q000378:metabolism*; D028861:Nuclear Pore Complex Proteins / Q000378:metabolism; D010750:Phosphoproteins / Q000378:metabolism; D060066:Protein Interaction Maps; D012319:RNA Polymerase II / Q000032:analysis / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000032:analysis / Q000235:genetics / Q000378:metabolism*; D014157:Transcription Factors / Q000378:metabolism; D015854:Up-Regulation
chemical_list: D002352:Carrier Proteins; C544940:IWR1 protein, S cerevisiae; D028884:Karyopherins; C077731:NUP100 protein, S cerevisiae; C077730:NUP116 protein, S cerevisiae; D028861:Nuclear Pore Complex Proteins; D010750:Phosphoproteins; C581284:Rtp1 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D014157:Transcription Factors; C075995:down-regulator of transcription 1; D012319:RNA Polymerase II; C580821:RPB2 protein, S cerevisiae; C112110:RPB3 protein, S cerevisiae