A homolog of FBP2/KSRP binds to localized mRNAs in Xenopus oocytes.
A Xenopus oocyte expression library was screened for proteins that bind to the 340-nucleotide localization element of Vg1 mRNA. Four different isolates encoded a Xenopus homolog of the human transcription factor, FUSE-binding protein 2 (FBP2). This protein has been independently identified as the splicing regulatory factor KSRP. The only significant difference between the Xenopus protein, designated VgRBP71, and KSRP is the absence of a 58 amino acid segment near the N-terminal of the former. In vivo binding assays show that VgRBP71 is associated with mRNAs localized to either the vegetal or animal hemispheres, but was not found with control mRNAs. Unlike other factors that bind to the localization element of Vg1 mRNA, VgRBP71 does not accumulate at the vegetal cortex with the mRNA; rather, it is present in the nucleus and throughout the cytoplasm at all stages of oogenesis. Cytoplasmic VgRBP71 appears to be most concentrated at the cell cortex. VgRBP71 interacts with Prrp, another protein that binds to the Vg1 localization element; this association does not require the presence of Vg1 mRNA.
Kroll
Todd T
TT
Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46556, USA.
Zhao
Wei-Meng
WM
Jiang
Can
C
Huber
Paul W
PW
D000595:Amino Acid Sequence; D000818:Animals; D015152:Blotting, Northern; D003593:Cytoplasm / Q000378:metabolism; D018076:DNA, Complementary / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D000939:Epitopes / Q000378:metabolism; D005347:Fibroblasts / Q000378:metabolism; D015723:Gene Library; D018613:Microscopy, Confocal; D008969:Molecular Sequence Data; D009474:Neurons / Q000378:metabolism; D009687:Nuclear Proteins / Q000378:metabolism; D009865:Oocytes / Q000378:metabolism; D010957:Plasmids / Q000378:metabolism; D011233:Precipitin Tests; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D012313:RNA / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D016601:RNA-Binding Proteins / Q000737:chemistry / Q000378:metabolism* / Q000502:physiology*; D017386:Sequence Homology, Amino Acid; D013997:Time Factors; D015534:Trans-Activators / Q000378:metabolism*; D020798:Two-Hybrid System Techniques; D014981:Xenopus / Q000196:embryology*; D029867:Xenopus Proteins / Q000737:chemistry / Q000378:metabolism* / Q000502:physiology*
D018076:DNA, Complementary; D000939:Epitopes; C471150:KHSRP protein, Xenopus; C105789:KHSRP protein, human; D009687:Nuclear Proteins; C426830:PRLH protein, Xenopus; D012333:RNA, Messenger; D016601:RNA-Binding Proteins; D015534:Trans-Activators; D029867:Xenopus Proteins; C446510:ZBP2 protein, Gallus gallus; D012313:RNA