Structure and Mechanism of Dimer-Monomer Transition of a Plant Poly(A)-Binding Protein upon RNA Interaction: Insights into Its Poly(A) Tail Assembly

Author(s):Show less -

Domingues, Mariane Noronha ^[1] ; Sforca, Mauricio Luis ^[1] ; Soprano, Adriana Santos ^[1] ; Lee, Jack ^[2] ; Campos Brasil de Souza, Tatiana de Arruda ^[3] ; Cassago, Alexandre ^[4] ; Portugal, Rodrigo Villares ^[4] ; de Mattos Zeri, Ana Carolina ^[1] ; Murakami, Mario Tyago ^[1] ; Sadanandom, Ari ^[2] ; Lopes de Oliveira, Paulo Sergio ^[1] ; Benedetti, Celso Eduardo ^[1]

Affiliation

^[1] Ctr Nacl Pesquisa Energia & Mat, Lab Nacl Biociencias, Campinas, SP - Brazil

^[2] Univ Durham, Sch Biol & Biomed Sci, Durham DH1, Durham - England

^[3] Fundacao Oswaldo Cruz, Inst Carlos Chagas, BR-81350010 Curitiba, Parana - Brazil

^[4] Ctr Nacl Pesquisa Energia & Mat, Lab Nacl Nanotecnol, Campinas, SP - Brazil

• Document type: Journal article
• Source: Journal of Molecular Biology; v. 427, n. 15, p. 2491-2506, JUL 31 2015.
• Web of Science Citations: 4

Abstract

Poly(A)-binding proteins (PABPs) play crucial roles in mRNA biogenesis, stability, transport and translational control in most eukaryotic cells. Although animal PABPs are well-studied proteins, the biological role, three-dimensional structure and RNA-binding mode of plant PABPs remain largely uncharacterized. Here, we report the structural features and RNA-binding mode of a Citrus sinensis PABP (CsPABPN1). CsPABPN1 has a domain architecture of nuclear PABPs (PABPNs) with a single RNA recognition motif (RRM) flanked by an acidic N-terminus and a GRPF-rich C-terminus. The RRM domain of CsPABPN1 displays virtually the same three-dimensional structure and poly(A)-binding mode of animal PABPNs. However, while the CsPABPN1 RRM domain specifically binds poly(A), the full-length protein also binds poly(U). CsPABPN1 localizes to the nucleus of plant cells and undergoes a dimer-monomer transition upon poly(A) interaction. We show that poly(A) binding by CsPABPN1 begins with the recognition of the RNA-binding sites RNP1 and RNP2, followed by interactions with residues of the 132 strands, which stabilize the dimer, thus leading to dimer dissociation. Like human PABPN1, CsPABPN1 also seems to form filaments in the presence of poly(A). Based on these data, we propose a structural model in which contiguous CsPABPN1 RRM monomers wrap around the RNA molecule creating a superhelical structure that could not only shield the poly(A) tail but also serve as a scaffold for the assembly of additional mRNA processing factors. (C) 2015 Elsevier Ltd. All rights reserved. (AU)

• FAPESP's process: 11/20468-1 - Molecular mechanisms involved in pathogen adaptation and virulence, host resistance and symptom development in citrus-bacteria interactions
• Grantee: Celso Eduardo Benedetti
• Support Opportunities: Research Projects - Thematic Grants