Mouse testis brain ribonucleic acid-binding protein/translin colocalizes with microtubules and is immunoprecipitated with messenger ribonucleic acids encoding myelin basic protein, alpha calmodulin kinase II, and protamines 1 and 2.
Testis brain RNA-binding protein (TB-RBP) is a sequence-dependent RNA-binding protein that binds to conserved Y and H sequence elements present in many brain and testis mRNAs. Using recombinant TB-RBP and a highly enriched tubulin fraction, we demonstrate here that recombinant TB-RBP binds to microtubules assembled in vitro. The interaction between recombinant TB-RBP and microtubules was inhibited by high salt and by the microtubule disassembling agents colcemid and calcium, but not by the microfilament-disassembling agent cytochalasin D. Confocal microscopy confirmed colocalization of TB-RBP and tubulin in the cytoplasm of male germ cells. An affinity-purified antibody prepared against recombinant TB-RBP specifically precipitated mRNAs encoding myelin basic protein and alpha calmodulin-dependent kinase II-two transported mRNAs, and protamines 1 and 2-two translationally regulated testicular mRNAs. These data indicate an intracellular association between TB-RBP and specific target mRNAs and suggest an involvement of TB-RBP in microtubule-dependent mRNA transport in the cytoplasm of cells.
Wu
X Q
XQ
Center for Research on Reproduction and Women's Health and Department of Obstetrics and Gynecology, University of Pennsylvania School of Medicine, Philadelphia, PA 19104, USA. HD 28832
Hecht
N B
NB
D000595:Amino Acid Sequence; D000818:Animals; D001921:Brain / Q000378:metabolism; D054732:Calcium-Calmodulin-Dependent Protein Kinase Type 2; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000235:genetics* / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000378:metabolism; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D008869:Microtubule-Associated Proteins / Q000276:immunology / Q000378:metabolism*; D008870:Microtubules / Q000378:metabolism*; D008969:Molecular Sequence Data; D004676:Myelin Basic Protein / Q000235:genetics* / Q000378:metabolism; D011233:Precipitin Tests; D011479:Protamines / Q000235:genetics* / Q000378:metabolism; D014176:Protein Biosynthesis; D012333:RNA, Messenger / Q000378:metabolism; D016601:RNA-Binding Proteins / Q000276:immunology / Q000378:metabolism*; D011994:Recombinant Proteins / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D013094:Spermatozoa / Q000378:metabolism
D004268:DNA-Binding Proteins; D008869:Microtubule-Associated Proteins; D004676:Myelin Basic Protein; C513176:Prm1 protein, mouse; D011479:Protamines; D012333:RNA, Messenger; D016601:RNA-Binding Proteins; D011994:Recombinant Proteins; C490551:STRBP protein, human; C498303:Tsn protein, mouse; C068621:protamine 2; D054732:Calcium-Calmodulin-Dependent Protein Kinase Type 2; D017871:Calcium-Calmodulin-Dependent Protein Kinases