title: Poly(A) polymerase (PAP) diversity in gene expression--star-PAP vs canonical PAP.
abstract: Almost all eukaryotic mRNAs acquire a poly(A) tail at the 3'-end by a concerted RNA processing event: cleavage and polyadenylation. The canonical PAP, PAPα, was considered the only nuclear PAP involved in general polyadenylation of mRNAs. A phosphoinositide-modulated nuclear PAP, Star-PAP, was then reported to regulate a select set of mRNAs in the cell. In addition, several non-canonical PAPs have been identified with diverse cellular functions. Further, canonical PAP itself exists in multiple isoforms thus illustrating the diversity of PAPs. In this review, we compare two nuclear PAPs, Star-PAP and PAPα with a general overview of PAP diversity in the cell. Emerging evidence suggests distinct niches of target pre-mRNAs for the two PAPs and that modulation of these PAPs regulates distinct cellular functions.
authors.affiliation: Cancer Research Program, Rajiv Gandhi Centre for Biotechnology, Thiruvananthapuram 695014, India. Electronic address: laishram@rgcb.res.in.
authors.forename: Rakesh S
authors.initials: RS
authors.lastname: Laishram
mesh_terms: D000818:Animals; D001483:Base Sequence; D001665:Binding Sites; D016384:Consensus Sequence; D005786:Gene Expression Regulation; D006801:Humans; D009713:Nucleotidyltransferases; D026723:Polyadenylation; D011062:Polynucleotide Adenylyltransferase / Q000502:physiology*; D011485:Protein Binding; D020033:Protein Isoforms / Q000502:physiology; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism*
chemical_list: D020033:Protein Isoforms; D012333:RNA, Messenger; D009713:Nucleotidyltransferases; C586325:TUT1 protein, human; D011062:Polynucleotide Adenylyltransferase
keywords: 3′-end processing; CKI; Canonical PAP; Oxidative stress; PAP isoforms; PAPα; PI4,5P(2); PIPKIα; Poly(A) polymerase (PAP); Polyadenylation; Star-PAP; Uridylation