OseIF3h Regulates Plant Growth and Pollen Development at Translational Level Presumably through Interaction with OsMTA2.

Yuqing Huang,Hao Chen,Xuejiao Liu,Peng Zheng,Jumin Tu

doi:10.3390/plants10061101

Abstract

The initiation stage of protein biosynthesis is a sophisticated process tightly regulated by numerous initiation factors and their associated components. However, the mechanism underlying translation initiation has not been completely understood in rice. Here, we showed knock-out mutation of the rice eukaryotic translation initiation factor 3 subunit h (OseIF3h) resulted in plant growth retardation and seed-setting rate reduction as compared to the wild type. Further investigation demonstrated an interaction between OseIF3h and OsMTA2 (mRNA adenosine methylase 2), a rice homolog of METTL3 (methyltransferase-like 3) in mammals, which provided new insight into how N6-methyladenosine (m6A) modification of messenger RNA (mRNA) is engaged in the translation initiation process in monocot species. Moreover, the RIP-seq (RNA immunoprecipitation sequencing) data suggested that OseIF3h was involved in multiple biological processes, including photosynthesis, cellular metabolic process, precursor metabolites, and energy generation. Therefore, we infer that OseIF3h interacts with OsMTA2 to target a particular subset of genes at translational level, regulating plant growth and pollen development.

Highlights

Protein synthesis is predominantly determined by many distinguishing factors at the initiation phase instead of the elongation or termination phase, contributing to instant, flexible and precise regulation over global translation [1]
EIF3h depletion caused a severe defect in meiosis, leading to a high frequency in either no spores or incomplete tetrads [11]
Further phenotypic analysis indicated that the loss of OseIF3h seriously affected plant growth (Figure 1B). oseif3h mutants were about 55 cm in height, which was significantly shorter than that of wild type 77 cm (Figure 1C)

Summary

Introduction

Protein synthesis is predominantly determined by many distinguishing factors at the initiation phase instead of the elongation or termination phase, contributing to instant, flexible and precise regulation over global translation [1]. Among these factors, eIF3 is a multicomponent complex and ubiquitously presents in all eukaryotic organisms. The eIF3h subunit presenting on the periphery of the eIF3 complex is an evolutionarily conserved 38-kDa MPN (Mpr1-Pad1-N-terminus) domain protein Proteins harboring this domain can work as members in constituting the COP9 signalosome, the 26S proteasome lid [6]. EIF3h functions as a device for translational governance of a certain subset of cellular mRNAs and exerts a profound impact on normal growth and development

Methods

Results

Conclusion