title: A retinoblastoma-binding protein related to a negative regulator of Ras in yeast.
abstract: The growth suppression function of the retinoblastoma protein (Rb) is though to be mediated by Rb binding to cellular proteins. p48 is one of the major proteins that binds to a putative functional domain at the carboxy terminus of the Rb protein. Here we report the isolation of a full-length complementary DNA (RbAp48) encoding p48. Complex formation between p48 and Rb occurs in vitro and in vivo, and apparently involves direct interaction between the proteins. Like Rb, p48 is a ubiquitously expressed nuclear protein. RbAp48 share sequence homology with MSI1, a negative regulator of the Ras-cyclic AMP pathway in the yeast Saccharomyces cerevisiae. Furthermore, like MSI1, human RbAp48 suppresses the heat-shock sensitivity of the yeast ira1 strains and RAS2Val19 strains. Interaction with p48 may be one of the mechanisms for suppression of growth mediated by Rb.
authors.affiliation: Center for Molecular Medicine, University of Texas, Health Science Center, San Antonio 78245-3207.
authors.forename: Y W
authors.initials: YW
authors.lastname: Qian
authors.forename: Y C
authors.initials: YC
authors.lastname: Wang
authors.forename: R E
authors.initials: RE
authors.lastname: Hollingsworth
authors.forename: D
authors.initials: D
authors.lastname: Jones
authors.forename: N
authors.initials: N
authors.lastname: Ling
authors.forename: E Y
authors.initials: EY
authors.lastname: Lee
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D002352:Carrier Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D056504:Chromatin Assembly Factor-1; D004268:DNA-Binding Proteins; D005656:Fungal Proteins / Q000737:chemistry*; D006358:Hot Temperature; D006801:Humans; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D011485:Protein Binding; D011994:Recombinant Proteins / Q000378:metabolism; D016160:Retinoblastoma Protein / Q000378:metabolism*; D056505:Retinoblastoma-Binding Protein 4; D012441:Saccharomyces cerevisiae / Q000502:physiology; D029701:Saccharomyces cerevisiae Proteins; D017386:Sequence Homology, Amino Acid; D014407:Tumor Cells, Cultured
chemical_list: D002352:Carrier Proteins; D056504:Chromatin Assembly Factor-1; D004268:DNA-Binding Proteins; D005656:Fungal Proteins; C061736:MSI1 protein, S cerevisiae; D009687:Nuclear Proteins; C082637:RBBP4 protein, human; D011994:Recombinant Proteins; D016160:Retinoblastoma Protein; D056505:Retinoblastoma-Binding Protein 4; D029701:Saccharomyces cerevisiae Proteins