title: Protein-protein interactions between the testis brain RNA-binding protein and the transitional endoplasmic reticulum ATPase, a cytoskeletal gamma actin and Trax in male germ cells and the brain.
abstract: Numerous functions have been proposed for the testis brain RNA-binding protein (TB-RBP) and its human homologue, Translin, ranging from mRNA transport and translational regulation to DNA rearrangement and repair. To gain insight into the likely functions of this 26 kDa protein, immunoprecipitation was used to identify proteins that interact with TB-RBP in mouse cytosolic extracts. Three proteins, the transitional endoplasmic reticulum ATPase, a cytoskeletal gamma actin, and Trax, were specifically immunoprecipitated with an affinity-purified antibody to recombinant mouse TB-RBP. In vitro binding assays with recombinant proteins and EM immunocytochemistry confirm that TB-RBP interacts with the TER ATPase in vitro and in vivo. Confocal microscopy has demonstrated that TB-RBP colocalizes with actin in the cytoplasm of male germ cells. The immunoprecipitation of Trax with TB-RBP confirms a published report demonstrating protein interactions between the two proteins in a yeast two-hybrid assay. These data support the hypothesis that TB-RBP serves as a link in attaching specific mRNAs to cytoskeletal structures and suggests an involvement for the ubiquitously expressed TER ATPase in intracellular and/or intercellular mRNA transport.
authors.affiliation: Center for Research on Reproduction and Women's Health, Department of Obstetrics and Gynecology, University of Pennsylvania School of Medicine, Philadelphia 19104, USA.
authors.forename: X Q
authors.initials: XQ
authors.lastname: Wu
authors.forename: S
authors.initials: S
authors.lastname: Lefrancois
authors.forename: C R
authors.initials: CR
authors.lastname: Morales
authors.forename: N B
authors.initials: NB
authors.lastname: Hecht
mesh_terms: D000199:Actins / Q000378:metabolism*; D000251:Adenosine Triphosphatases / Q000235:genetics / Q000378:metabolism*; D000595:Amino Acid Sequence; D000818:Animals; D001921:Brain / Q000378:metabolism; D002352:Carrier Proteins / Q000378:metabolism*; D002462:Cell Membrane / Q000378:metabolism; D003599:Cytoskeleton / Q000378:metabolism; D004268:DNA-Binding Proteins; D004721:Endoplasmic Reticulum / Q000201:enzymology*; D007150:Immunohistochemistry; D008297:Male; D051379:Mice; D018613:Microscopy, Confocal; D008854:Microscopy, Electron; D008869:Microtubule-Associated Proteins / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000378:metabolism*; D011233:Precipitin Tests; D011485:Protein Binding / Q000235:genetics; D016601:RNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D013094:Spermatozoa / Q000737:chemistry / Q000378:metabolism* / Q000648:ultrastructure
chemical_list: D000199:Actins; D002352:Carrier Proteins; D004268:DNA-Binding Proteins; D008869:Microtubule-Associated Proteins; D009687:Nuclear Proteins; D016601:RNA-Binding Proteins; D011993:Recombinant Fusion Proteins; C490551:STRBP protein, human; C498303:Tsn protein, mouse; C498306:Tsnax protein, mouse; D000251:Adenosine Triphosphatases; C091277:TER ATPase