A novel set of nuclear localization signals determine distributions of the alphaCP RNA-binding proteins.

AlphaCPs comprise a subfamily of KH-domain-containing RNA-binding proteins with specificity for C-rich pyrimidine tracts. These proteins play pivotal roles in a broad spectrum of posttranscriptional events. The five major alphaCP isoforms are encoded by four dispersed loci.

A set of highly conserved RNA-binding proteins, alphaCP-1 and alphaCP-2, implicated in mRNA stabilization, are coexpressed from an intronless gene and its intron-containing paralog.

Gene families normally expand by segmental genomic duplication and subsequent sequence divergence. Although copies of partially or fully processed mRNA transcripts are occasionally retrotransposed into the genome, they are usually nonfunctional ("processed pseudogenes"). The two major cytoplasmic poly(C)-binding proteins in mammalian cells, alphaCP-1 and alphaCP-2, are implicated in a spectrum of post-transcriptional controls.

Assembly of the alpha-globin mRNA stability complex reflects binary interaction between the pyrimidine-rich 3' untranslated region determinant and poly(C) binding protein alphaCP.

Globin mRNAs accumulate to 95% of total cellular mRNA during terminal erythroid differentiation, reflecting their extraordinary stability. The stability of human alpha-globin mRNA is paralleled by formation of a sequence-specific RNA-protein (RNP) complex at a pyrimidine-rich site within its 3' untranslated region (3'UTR), the alpha-complex. The proteins of the alpha-complex are widely expressed.

Identification of DNA binding proteins in vaccinia virus by DNA-protein crosslinking.

DNA binding proteins of vaccinia virus (VV) virions, strain LIVP, have been studied by their covalent crosslinking to DNA, using two-dimensional gel retardation electrophoresis of crosslinked DNA and proteins as well as the 'protein image' hybridization assay. Five proteins with molecular masses of 16, 25, 27, 41 and 54 kDa, respectively, associated with all analysed DNA sequences, including early and late genes and their promoters, have been identified.