Molecular evolution of RRM-containing proteins and glycine-rich RNA-binding proteins in plants

Judith Gomez-Porras,Dorothee Staiger,Martin Lewinski,Diego Mauricio Riaño-Pachón

doi:10.1038/npre.2011.5970.1

Abstract

Abstract Background: In angiosperms, RNA-binding proteins with an RNA recognition motif (RRM)-type RNA interaction domain play an important role in developmental and environmental responses. Despite their pivotal role, a comprehensive analysis of their number and diversity has only been performed in Arabidopsis so far. Results: Here we present a detailed phylogenetic analysis of RRM-containing proteins in plants, the red algae Cyanidioschyzon merolae and cyanobacteria. We identified two major events during the diversification of the RRM in plants, one at the emergence of green plants, and the other at the water-to-land transition. We focused on proteins that combine a single RRM with a glycine-rich stretch, known as glycine-rich RNA-binding proteins (GRPs). We found that GRPs are present in cyanobacteria, however plant and cyanobacterial GRPs are not of monophyletic origin. We provide evidence that plant GRPs form a polyphyletic group.*Conclusion:*Our work provides insights into the origin of GRPs in plants. We determined that the RRM from plants and cyanobacteria do not have a common origin. We could also determine that the acquisition of the glycine-rich stretch has happened at least on three separate occasions during the evolution of GRPs. One event led to the emergence of cyanobacterial GRPs, while later acquisition events led to the emergence of GRPs in the green lineage. No GRPs were found in red or marine green algae. We found a subgroup of GRPs exclusive to land plants, and its appearance may be linked to challenges related to the water-to-land transition.

Highlights

In angiosperms, RNA-binding proteins with an RNA recognition motif (RRM)-type RNA interaction domain play an important role in developmental and environmental responses
We focused on proteins that combine a single RRM with a glycine-rich stretch, known as glycine-rich RNA-binding proteins (GRPs)
One event led to the emergence of cyanobacterial GRPs, while later acquisition events led to the emergence of GRPs in the green lineage

Summary

Introduction

RNA-binding proteins with an RNA recognition motif (RRM)-type RNA interaction domain play an important role in developmental and environmental responses. Despite their pivotal role, a comprehensive analysis of their number and diversity has only been performed in Arabidopsis so far. GRPs have been found in a wide range of plant species including maize [6], tobacco [7], barley [8], sorghum [9], white mustard [10], Arabidopsis [11], rice [12] and moss [13] They have been identified in several cyanobacteria. Our phylogenetic analysis allows us to conclude that neither the cyanobacterial nor the plant GRPs are monophyletic

Methods

Results

Conclusion