Abstract
ER retention receptor is a seven trans-membrane protein that plays pivotal roles in function and integrity of endoplasmic reticulum (ER). Insertional mutagenesis of Magnaporthe oryzae identified MoERR1 as a pathogenicity gene encoding putative ER retention receptor orthologous to ERD2 in Saccharomyces cerevisiae. Search through the genome identified that M. oryzae possesses another ortholog of ERD2, which is designated as MoERR2. When MoERR1 and MoERR2 were tagged with GFP, both were localized to ER. Targeted disruption of MoERR1 showed pleiotropic effects on phenotypes, while deletion of MoERR2 had no effect on phenotypes we examined. The disruption mutant of MoERR1 showed growth retardation and produced significantly reduced number of conidia with aberrant morphology. Appressoria from the mutant were unable to penetrate into plant tissues presumably due to defect in cell wall integrity, thereby rendering the mutant non-pathogenic. The MoERR1 mutant also appeared to display abnormal ER structure and mis-regulation of genes involved in chaperone function and unfolded protein response under ER stress condition. Taken together, these results suggest that MoERR1 is a ER retention receptor required for function and integrity of ER, and that MoERR1-mediated ER functionalities are essential for fungal development and pathogenesis.
Highlights
Endoplasmic reticulum (ER) is a membranous cellular structure, which is comprised of interconnected network of tubules, vesicles, and cisternae within eukaryotic cells
Upon identification of putative endoplasmic reticulum (ER) retention receptors in M. oryzae, we examined if they are membrane proteins, using hydropathy plot, since ERD2 in S. cerevisiae is known as a seven trans-membrane protein
We investigated the functions of two genes (MoERR1 and MoERR2) encoding putative ER retention protein in M. oryzae during pathogenic development, one of which is tagged by T-DNA insertion (MoERR1)
Summary
Endoplasmic reticulum (ER) is a membranous cellular structure, which is comprised of interconnected network of tubules, vesicles, and cisternae within eukaryotic cells. ER is known to play roles for post-translational modification, folding and translocation of proteins These proteins are glycosylated, folded, and/or assembled into multi-subunit complex following their co-translational insertion into the ER lumen or ER membrane before being transported in vesicles to the Golgi apparatus and subsequently further downstream on the secretory pathway[1]. Such ER functionalities are dependent on ER-resident proteins such as chaperons, post-translational modification enzymes, and proteins involved in unfolded protein response (UPR). Our study demonstrates the importance of MoERR1-mediated function and integrity of ER in fungal pathogenesis
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
