Plant coilin: structural characteristics and RNA-binding properties

PLoS One. 2013;8(1):e53571. doi: 10.1371/journal.pone.0053571. Epub 2013 Jan 8.

Abstract

Cajal bodies (CBs) are dynamic subnuclear compartments involved in the biogenesis of ribonucleoproteins. Coilin is a major structural scaffolding protein necessary for CB formation, composition and activity. The predicted secondary structure of Arabidopsis thaliana coilin (Atcoilin) suggests that the protein is composed of three main domains. Analysis of the physical properties of deletion mutants indicates that Atcoilin might consist of an N-terminal globular domain, a central highly disordered domain and a C-terminal domain containing a presumable Tudor-like structure adjacent to a disordered C terminus. Despite the low homology in amino acid sequences, a similar type of domain organization is likely shared by human and animal coilin proteins and coilin-like proteins of various plant species. Atcoilin is able to bind RNA effectively and in a non-specific manner. This activity is provided by three RNA-binding sites: two sets of basic amino acids in the N-terminal domain and one set in the central domain. Interaction with RNA induces the multimerization of the Atcoilin molecule, a consequence of the structural alterations in the N-terminal domain. The interaction with RNA and subsequent multimerization may facilitate coilin's function as a scaffolding protein. A model of the N-terminal domain is also proposed.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Arabidopsis / genetics
  • Arabidopsis / metabolism
  • Arabidopsis Proteins / chemistry*
  • Arabidopsis Proteins / genetics
  • Arabidopsis Proteins / metabolism*
  • Binding Sites / genetics
  • Humans
  • Models, Molecular
  • Nuclear Proteins / chemistry*
  • Nuclear Proteins / genetics
  • Nuclear Proteins / metabolism*
  • Protein Binding / genetics
  • Protein Multimerization
  • Protein Structure, Tertiary / genetics
  • RNA, Plant / metabolism*
  • RNA-Binding Proteins / chemistry*
  • RNA-Binding Proteins / genetics
  • RNA-Binding Proteins / metabolism*

Substances

  • Arabidopsis Proteins
  • Atcoilin protein, Arabidopsis
  • Nuclear Proteins
  • RNA, Plant
  • RNA-Binding Proteins
  • p80-coilin

Grant support

This work was supported by RFBR grant 10-04-0522a. The work of A.J.L. and M.T. was supported by funding from Scottish Government Rural and Environmental Science and Analytical Services Division. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.