Characterization of a Drosophila homologue of the 160-kDa subunit of the cleavage and polyadenylation specificity factor CPSF

• Published in: Molecular & general genetics 1998-04, Vol.257 (6), p.672-680
• Main Authors: Salinas, C.A, Sinclair, D.A.R, O'Hare, K, Brock, H.W
• Format: Article
• Language: English
• Subjects: Amino Acid Sequence; amino acid sequences; animal cuticle; Animals; binding proteins; chemical reactions; cloning; complementary DNA; cpsf gene; degradation; deletions; Drosophila - genetics; Drosophila - metabolism; Drosophila melanogaster; Drosophila Proteins; embryogenesis; gene expression; genes; genetic complementation; Insect Proteins - chemistry; Insect Proteins - metabolism; introns; messenger RNA; Molecular Sequence Data; mRNA Cleavage and Polyadenylation Factors; mutants; mutation; Nuclear Proteins; nucleotide sequences; nucleotidyltransferases; phenotype; poly(a) polymerase; precursors; RNA-Binding Proteins - chemistry; RNA-Binding Proteins - genetics; RNA-Binding Proteins - metabolism; Sequence Alignment; Sequence Homology, Amino Acid; su(f) gene; viability
• ISSN: 0026-8925; 1432-1874
• DOI: 10.1007/s004380050696

Processing of the 3' end of mRNA precursors depends on several proteins. The multisubunit cleavage and polyadenylation specificity factor (CPSF) is required for cleavage of the mRNA precursor as well as polyadenylation. CPSF interacts with the cleavage stimulatory factor complex (CstF), and this interaction increases the specificity of binding. Following cleavage downstream of the AAUAAA site, CPSF and poly(A) polymerase (PAP) are required for efficient polyadenylation. Recently, it has been shown that 160-kDa subunit of CPSF interacts directly with the 77-kDa subunit of CstF, which is homologous to the product encoded by the Drosophila gene su(f), and with PAP. Here we report the cloning and characterization of a Drosophila homologue of CPSF-160. The 1329-amino acid dCPSF protein exhibits about 45% and 20% sequence identity, respectively, to its mammalian and yeast counterparts over its entire length. We show that the CPSF homologue is expressed throughout development and that CPSF is essential for viability. Mutations in the cpsf gene did not alter the phenotype of homozygous su(f) mutations, suggesting that, for most genes, processing of 3' termini is not sensitive to small changes in cpsf and su(f) dosage.