Open AccessRNA binding properties and evoultionary conservation of the Xenopus multifinger protein Xfin
Author(s) -
Massimiliano Andreazzoli,
Stefania De Lucchini,
Mario Costa,
Giuseppina Barsacchi
Publication year - 1993
Publication title -
nucleic acids research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 9.008
H-Index - 537
eISSN - 1362-4954
pISSN - 0305-1048
DOI - 10.1093/nar/21.18.4218
Subject(s) - biology , xenopus , phosphoprotein , rna , cytoplasm , rna binding protein , phosphorylation , complementary dna , conserved sequence , microbiology and biotechnology , zinc finger , fusion protein , biochemistry , peptide sequence , transcription factor , gene , recombinant dna
Xfin is a Xenopus zinc finger protein which is expressed in the cytoplasm of the oocyte and throughout embryogenesis, as well as in the cytoplasm of some specific and highly differentiated cell types (De Lucchini et al., Mech. Dev. 36, 31-40, 1991). In this paper we present a characterization of some structural features of the protein and of its nucleic acid binding properties. We found that Xfin is a phosphoprotein, is present in the soluble fraction of the cytoplasm, and is actively phosphorylated in cytosolic extracts. Several putative phosphorylation sites are present in the cDNA-derived protein sequence, mostly located at specific positions within the Zn-fingers. In an in vitro assay a fusion protein containing part of the finger region of Xfin exhibits specific binding to a poly (G) RNA homopolymer, while it does not bind DNA. The RNA binding activity of the protein is significantly enhanced by phosphorylation. A putative Xfin homolog, which appears to be evolutionarily conserved with regard to size, cytoplasmic expression and antigenic specificity, is present in representatives of five Vertebrate classes. Taken together, these results may suggest that, by virtue of its RNA binding activity modulated through phosphorylation, Xfin could serve some evolutionarily conserved function in post-transcriptional regulation processes.