Three new members of the RNP protein family in Xenopus

• Published in: Nucleic acids research 1993-02, Vol.21 (4), p.999-1006
• Main Authors: Good, Peter J., Rebbert, Martha L., Dawid, lgor B.
• Format: Article
• Language: English
• Subjects: Amino Acid Sequence; Analytical, structural and metabolic biochemistry; Animals; Base Sequence; Biological and medical sciences; Cloning, Molecular; containing; Cytoplasm - metabolism; Fundamental and applied biological sciences. Psychology; Gene Expression; gene products; genes; Heterogeneous Nuclear Ribonucleoprotein A1; Heterogeneous-Nuclear Ribonucleoprotein Group A-B; Heterogeneous-Nuclear Ribonucleoproteins; hnRNA; Humans; isoforms; Microinjections; Molecular Sequence Data; Nerve Tissue Proteins - genetics; nrp1 gene; Nucleic acids; nucleotide sequence; Oocytes - metabolism; Polymerase Chain Reaction; predictions; ribonucleoproteins; Ribonucleoproteins - chemistry; Ribonucleoproteins - genetics; Ribonucleoproteins - metabolism; Rna, ribonucleoproteins; Sequence Homology, Amino Acid; Xenopus; Xenopus Proteins; xrp1 gene
• ISSN: 0305-1048; 1362-4962
• DOI: 10.1093/nar/21.4.999

Many RNP proteins contain one or more copies of the RNA recognition motif (RRM) and are thought to be involved in cellular RNA metabolism. We have previously characterized in Xenopus a nervous system specific gene, nrp1, that is more simliar to the hnRNP A/B proteins than to other known proteins (K.Richter, P.J.Good, and I.B.Dawid (1990), New Blol. 2,556-565). PCR amplification with degenerate primers was used to identify additional cDNAs encoding two RRMs in Xenopus. Three previously uncharacterlzed genes were identified. Two genes encode hnRNP A/B proteins with two RRMs and a glycine-rich domain. One of these is the Xenopus homoiog of the human A2/B1 gene; the other, named hnRNP A3, is similar to both the A1 and A2 hnRNP genes. The Xenopus hnRNP A1, A2 and A3 genes are expressed throughout development and in all adult tissues. Multiple protein isoforms for the hnRNP A2 gene are predicted that differ by the insertion of short peptide sequences in the glycine-rich domain. The third newly isolated gene, named xrp1, encodes a protein that is related by sequence to the nrpl protein but is expressed ubiquitously. Despite the similarity to nuclear RNP proteins, both the nrp1 and xrp1 proteins are localized to the cytoplasm in the Xenopus oocyte. The xrp1 gene may have a function in all cells that is similar to that executed by nrp1 specifically within the nervous system.