A Xenopus protein related to hnRNP I has a role in cytoplasmic RNA localization.
Cytoplasmic localization of mRNA molecules is a powerful mechanism for generating cell polarity. In vertebrates, one paradigm is localization of Vg1 RNA within the Xenopus oocyte, a process directed by recognition of a localization element within the Vg1 3' UTR. We show that specific base changes within the localization element abolish both localization in vivo and binding in vitro by a single protein, VgRBP60. VgRBP60 is homologous to a human hnRNP protein, hnRNP I, and combined immunolocalization and in situ hybridization demonstrate striking colocalization of hnRNP I and Vg1 RNA within the vegetal cytoplasm of the Xenopus oocyte. These results implicate a novel role in cytoplasmic RNA transport for this family of nuclear RNA-binding proteins.
Cote
C A
CA
Department of Molecular Biology, Cell Biology, and Biochemistry, Brown University, Providence, Rhode Island 02912, USA.
Gautreau
D
D
Denegre
J M
JM
Kress
T L
TL
Terry
N A
NA
Mowry
K L
KL
D020413:3' Untranslated Regions; D000818:Animals; D001692:Biological Transport; D002451:Cell Compartmentation; D016764:Cell Polarity; D003001:Cloning, Molecular; D003593:Cytoplasm / Q000737:chemistry; D006023:Glycoproteins / Q000235:genetics*; D008969:Molecular Sequence Data; D009154:Mutation; D009687:Nuclear Proteins / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism; D009865:Oocytes / Q000737:chemistry; D038941:Polypyrimidine Tract-Binding Protein; D011485:Protein Binding; D012333:RNA, Messenger / Q000302:isolation & purification* / Q000378:metabolism; D016601:RNA-Binding Proteins / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism; D012261:Ribonucleoproteins / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism; D016212:Transforming Growth Factor beta; D014981:Xenopus; D029867:Xenopus Proteins
D020413:3' Untranslated Regions; C513103:GDF1 protein, Xenopus; D006023:Glycoproteins; D009687:Nuclear Proteins; D012333:RNA, Messenger; D016601:RNA-Binding Proteins; D012261:Ribonucleoproteins; D016212:Transforming Growth Factor beta; D029867:Xenopus Proteins; D038941:Polypyrimidine Tract-Binding Protein