New Evidence for Differential Roles of L10 Ribosomal Proteins from Arabidopsis

Abstract

The RIBOSOMAL PROTEIN L10 (RPL10) is an integral component of the eukaryotic ribosome large subunit. Besides being a constituent of ribosomes and participating in protein translation, additional extraribosomal functions in the nucleus have been described for RPL10 in different organisms. Previously, we demonstrated that Arabidopsis (Arabidopsis thaliana) RPL10 genes are involved in development and translation under ultraviolet B (UV-B) stress. In this work, transgenic plants expressing Pro RPL10 :b-glucuronidase fusions show that, while AtRPL10A and AtRPL10B are expressed both in the female and male reproductive organs, AtRPL10C expression is restricted to pollen grains. Moreover, the characterization of double rpl10 mutants indicates that the three AtRPL10s differentially contribute to the total RPL10 activity in the male gametophyte. All three AtRPL10 proteins mainly accumulate in the cytosol but also in the nucleus, suggesting extraribosomal functions. After UV-B treatment, only AtRPL10B localization increases in the nuclei. We also here demonstrate that the three AtRPL10 genes can complement a yeast RPL10 mutant. Finally, the involvement of RPL10B and RPL10C in UV-B responses was analyzed by two-dimensional gels followed by mass spectrometry. Overall, our data provide new evidence about the nonredundant roles of RPL10 proteins in Arabidopsis.

Combined haploinsufficiency and purifying selection drive retention of RPL36a paralogs in Arabidopsis

“…Interestingly, we found RPL36aA to be expressed at higher levels than API2 in wild-type plants, suggesting that the stronger effect caused by the rpl36aa mutation is due to the fact that RPL36aA is the main contributor of RPL36a subunits. Our results favor the hypothesis that, at least in plants, the phenotypic differences observed between mutant alleles of paralogous genes, which have been reported in some cases3638, might result from differences in the expression patterns or the expression levels of individual paralogous proteins, rather than from the differential specificity for certain mRNAs of an heterogeneous population of ribosomes1719394041.…”

Increase in ribosomal proteins activity: Translational reprogramming inVanilla planifoliaJacks., againstFusariuminfection

“…Regarding the expression of RPL10, RPS13 and RPl23aB, and its possible role in the response of vanilla to Fusarium , in addition to the fact that the induction of RPL10, RPS13 has already been reported in response to pathogens in plants, it has also been documented that mutation of the Arabidopsis RPL10 gene causes lethality of the female gametophyte; while its overexpression complements this phenotype with the recovery of dwarfism in the mutant of the ACL5 gene, also in Arabidopsis (Imai et al, 2008). In this way, in Arabidopsis RPL10 and RPL10C, they were induced under UV-B stress conditions, a fact that was also observed in maize plants (Casati and Virginia, 2003, Ferreyra et al, 2013). Mutations in RPS13A result in a reduction of cell division, in the retardation of flowering, and in the retardation of the growth of shoots and leaves (Ito et al, 2000).…”

Mechanism of Cytoplasmic mRNA Translation

“…This last concept was detailed by Horiguchi et al (2012), but definitive examples of RP gene paralogs of distinct function remain limited. A possible example is provided by the Arabidopsis RPL10 paralogs, which appear to have non-redundant functions in male gametophyte development (Falcone Ferreyra et al, 2010;Falcone Ferreyra et al, 2013). However, it is necessary to rule out the possibility that RPL10 may have an extra-ribosomal function, as shown for a number of RPs in diverse eukaryotes (Warner and McIntosh, 2009;Xue and Barna, 2012).…”