title: Recognition of polyadenosine RNA by the zinc finger domain of nuclear poly(A) RNA-binding protein 2 (Nab2) is required for correct mRNA 3'-end formation.
abstract: Proteins bound to the poly(A) tail of mRNA transcripts, called poly(A)-binding proteins (Pabs), play critical roles in regulating RNA stability, translation, and nuclear export. Like many mRNA-binding proteins that modulate post-transcriptional processing events, assigning specific functions to Pabs is challenging because these processing events are tightly coupled to one another. To investigate the role that a novel class of zinc finger-containing Pabs plays in these coupled processes, we defined the mode of polyadenosine RNA recognition for the conserved Saccharomyces cerevisiae Nab2 protein and assessed in vivo consequences caused by disruption of RNA binding. The polyadenosine RNA recognition domain of Nab2 consists of three tandem Cys-Cys-Cys-His (CCCH) zinc fingers. Cells expressing mutant Nab2 proteins with decreased binding to polyadenosine RNA show growth defects as well as defects in poly(A) tail length but do not accumulate poly(A) RNA in the nucleus. We also demonstrate genetic interactions between mutant nab2 alleles and mutant alleles of the mRNA 3'-end processing machinery. Together, these data provide strong evidence that Nab2 binding to RNA is critical for proper control of poly(A) tail length.
authors.affiliation: Departments of Biochemistry, Emory University School ofMedicine, Atlanta, Georgia 30322, USA.
authors.forename: Seth M
authors.initials: SM
authors.lastname: Kelly
authors.forename: Sara W
authors.initials: SW
authors.lastname: Leung
authors.forename: Luciano H
authors.initials: LH
authors.lastname: Apponi
authors.forename: Anna M
authors.initials: AM
authors.lastname: Bramley
authors.forename: Elizabeth J
authors.initials: EJ
authors.lastname: Tran
authors.forename: Julia A
authors.initials: JA
authors.lastname: Chekanova
authors.forename: Susan R
authors.initials: SR
authors.lastname: Wente
authors.forename: Anita H
authors.initials: AH
authors.lastname: Corbett
mesh_terms: D000241:Adenosine / Q000378:metabolism*; D002467:Cell Nucleus; D009154:Mutation; D029543:Nucleocytoplasmic Transport Proteins / Q000378:metabolism*; D011108:Polymers / Q000378:metabolism*; D011485:Protein Binding; D039104:RNA 3' Polyadenylation Signals / Q000502:physiology*; D012331:RNA, Fungal / Q000378:metabolism*; D012333:RNA, Messenger / Q000737:chemistry / Q000378:metabolism; D016601:RNA-Binding Proteins / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000378:metabolism*; D016335:Zinc Fingers
chemical_list: C080773:NAB2 protein, S cerevisiae; D029543:Nucleocytoplasmic Transport Proteins; D011108:Polymers; D012331:RNA, Fungal; D012333:RNA, Messenger; D016601:RNA-Binding Proteins; D029701:Saccharomyces cerevisiae Proteins; C069424:polyadenosine; D000241:Adenosine