title: The poly A polymerase Star-PAP controls 3'-end cleavage by promoting CPSF interaction and specificity toward the pre-mRNA.
abstract: Star-PAP is a poly (A) polymerase (PAP) that is putatively required for 3'-end cleavage and polyadenylation of a select set of pre-messenger RNAs (mRNAs), including heme oxygenase (HO-1) mRNA. To investigate the underlying mechanism, the cleavage and polyadenylation of pre-mRNA was reconstituted with nuclear lysates. siRNA knockdown of Star-PAP abolished cleavage of HO-1, and this phenotype could be rescued by recombinant Star-PAP but not PAPα. Star-PAP directly associated with cleavage and polyadenylation specificity factor (CPSF) 160 and 73 subunits and also the targeted pre-mRNA. In vitro and in vivo Star-PAP was required for the stable association of CPSF complex to pre-mRNA and then CPSF 73 specifically cleaved the mRNA at the 3'-cleavage site. This mechanism is distinct from canonical PAPα, which is recruited to the cleavage complex by interacting with CPSF 160. The data support a model where Star-PAP binds to the RNA, recruits the CPSF complex to the 3'-end of pre-mRNA and then defines cleavage by CPSF 73 and subsequent polyadenylation of its target mRNAs.
authors.affiliation: Department of Pharmacology, University of Wisconsin, Medical Science Center, Madison, WI 53706, USA.
authors.forename: Rakesh S
authors.initials: RS
authors.lastname: Laishram
authors.forename: Richard A
authors.initials: RA
authors.lastname: Anderson
mesh_terms: D002457:Cell Extracts; D002460:Cell Line; D039223:Cleavage And Polyadenylation Specificity Factor / Q000378:metabolism*; D055785:Gene Knockdown Techniques; D051547:Heme Oxygenase-1 / Q000235:genetics; D006801:Humans; D011062:Polynucleotide Adenylyltransferase / Q000378:metabolism*; D012322:RNA Precursors / Q000378:metabolism*; D012323:RNA Processing, Post-Transcriptional; D034741:RNA, Small Interfering / Q000235:genetics / Q000378:metabolism; D012680:Sensitivity and Specificity
chemical_list: D002457:Cell Extracts; D039223:Cleavage And Polyadenylation Specificity Factor; D012322:RNA Precursors; D034741:RNA, Small Interfering; C496541:HMOX1 protein, human; D051547:Heme Oxygenase-1; D011062:Polynucleotide Adenylyltransferase