Characterization of cellular nucleic acid binding protein from Xenopus laevis: expression in all three germ layers during early development.
The Xenopus CNBP homologue (XCNBP) has been cloned from stage 14 neurula. XCNBP encodes a 18.4-kDa protein containing seven highly conserved zinc finger (Zn-finger) repeats (CX2CX4HX4CX2), with sequence similarity to human, mouse, rat, and yeast CNBP. A unique feature of XCNBP is that it contains a 10 amino acid (aa) deletion in the linker region between Zn-fingers 1 and 2, immediately downstream from an alternatively spliced exon of human CNBP isoforms. A similar deletion is found in mouse and yeast CNBP proteins. The deleted region lacks potential PEST and casein kinase II phosphorylation sites. Because CNBP proteins from a variety of species contain deletions in a similar region, these results suggest that the pattern of alternative processing of CNBP isoforms is highly conserved among metazoa and unicellular eukaryotes. XCNBP RNA is initially maternally derived and is widely expressed throughout early development at the gastrula, neurula, and tailbud stages. At the early gastrula stage, XCNBP is expressed in ectodermal, endodermal, and mesodermal germ layers. Previous data have demonstrated the presence of CNBP in the cytoplasm and nucleus. The interactions of CNBP with single-stranded DNA and RNA suggest that CNBP may serve dual functions in transcriptional and translational regulation in a wide variety of tissues during development.
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Department of Medicine, University of Arizona Health Sciences Center, University Heart Center, Tucson, Arizona 85724, USA. iflink@u.arizona.edu
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D017398:Alternative Splicing; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular; D017124:Conserved Sequence; D017931:DNA Primers / Q000235:genetics; D004268:DNA-Binding Proteins / Q000235:genetics* / Q000378:metabolism; D005260:Female; D018507:Gene Expression Regulation, Developmental; D006801:Humans; D017403:In Situ Hybridization; D051379:Mice; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D016601:RNA-Binding Proteins; D051381:Rats; D017386:Sequence Homology, Amino Acid; D029867:Xenopus Proteins; D014982:Xenopus laevis / Q000196:embryology* / Q000235:genetics* / Q000378:metabolism; D016335:Zinc Fingers / Q000235:genetics
D017931:DNA Primers; D004268:DNA-Binding Proteins; D012333:RNA, Messenger; D016601:RNA-Binding Proteins; D029867:Xenopus Proteins; C499013:CNBP protein, Xenopus; C433227:CNBP protein, human; C499018:Cnbp protein, rat; C499012:Cnbp protein, mouse