Blast fungus unconventional effector secretion sorting requires pre-Golgi compartment protein MoGrh1
- 1University of Nebraska-Lincoln
Abstract
Brefeldin A (BFA)-resistant unconventional protein secretion (UPS) is documented in cellular systems across taxa and has roles in disease, but mechanistic details remain sparse. The blast fungus Magnaporthe oryzae uses Golgi-bypass UPS to deploy plant immunity-suppressing cytoplasmic effector proteins into host rice cells to establish infection. However, few M. oryzae UPS components are known, and connections to other cellular processes are undefined. Here, using live-cell imaging of M. oryzae mutant strains, we show that MoGrh1, a resident of the pre-Golgi, BFA-resistant ER-Golgi intermediate compartment (ERGIC), is required for UPS cargo sorting under the autophagy-inducing conditions of early host cell colonization. The loss of MoGRH1 abolished UPS, with cytoplasmic effectors misrouted through a BFA-sensitive secretion pathway instead. Treatment with autophagy-suppressing -ketoglutarate, a preferred carbon source, reconstituted unconventional secretion in {Delta}grh1, restoring fungal growth in host cells. We conclude that MoGrh1 supports UPS cargo sorting under the nutrient-limiting conditions of early host cell infection, linking the ERGIC and autophagy to disease-causing effector secretion in a devastating plant pathogen.
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BibTeX
@misc{dulal2026blast,
title = {{Blast fungus unconventional effector secretion sorting requires pre-Golgi compartment protein MoGrh1}},
author = {N. Dulal and R. A. Wilson},
howpublished = {bioRxiv},
year = {2026},
month = oct,
doi = {10.64898/2026.10.06.757164},
url = {https://www.biorxiv.org/content/10.64898/2026.10.06.757164v1},
note = {CC BY-NC-ND},
}
RIS
TY - UNPB
TI - Blast fungus unconventional effector secretion sorting requires pre-Golgi compartment protein MoGrh1
AU - N. Dulal
AU - R. A. Wilson
PY - 2026
DA - 2026/10/06
PB - bioRxiv
DO - 10.64898/2026.10.06.757164
UR - https://www.biorxiv.org/content/10.64898/2026.10.06.757164v1
AB - Brefeldin A (BFA)-resistant unconventional protein secretion (UPS) is documented in cellular systems across taxa and has roles in disease, but mechanistic details remain sparse. The blast fungus Magnaporthe oryzae uses Golgi-bypass UPS to deploy plant immunity-suppressing cytoplasmic effector proteins into host rice cells to establish infection. However, few M. oryzae UPS components are known, and connections to other cellular processes are undefined. Here, using live-cell imaging of M. oryzae mutant strains, we show that MoGrh1, a resident of the pre-Golgi, BFA-resistant ER-Golgi intermediate compartment (ERGIC), is required for UPS cargo sorting under the autophagy-inducing conditions of early host cell colonization. The loss of MoGRH1 abolished UPS, with cytoplasmic effectors misrouted through a BFA-sensitive secretion pathway instead. Treatment with autophagy-suppressing -ketoglutarate, a preferred carbon source, reconstituted unconventional secretion in {Delta}grh1, restoring fungal growth in host cells. We conclude that MoGrh1 supports UPS cargo sorting under the nutrient-limiting conditions of early host cell infection, linking the ERGIC and autophagy to disease-causing effector secretion in a devastating plant pathogen.
ER -