Exo84c interacts with VAP27 to regulate exocytotic compartment degradation and stigma senescence

Zhang, Tong; Li, Yifan; Li, Chengyang; Zang, Jingze; Gao, Erlin; Kroon, Johan T.; Qu, Xiaolu; Hussey, Patrick J.; Wang, Pengwei

Abstract

In plants, exocyst subunit isoforms exhibit significant functional diversity in that they are involved in either protein secretion or autophagy, both of which are essential for plant development and survival. Although the molecular basis of autophagy is widely reported, its contribution to plant reproduction is not very clear. Here, we have identified Exo84c, a higher plant-specific Exo84 isoform, as having a unique function in modulating exocytotic compartment degradation during stigmatic tissue senescence. This process is achieved through its interaction with the ER localised VAP27 proteins, which regulate the turnover of Exo84c through the autophagy pathway. VAP27 recruits Exo84c onto the ER membrane as well as numerous ER-derived autophagosomes that are labelled with ATG8. These Exo84c/exocyst and VAP27 positive structures are accumulated in the vacuole for degradation, and this process is partially perturbed in the exo84c knock-out mutants. Interestingly, the exo84c mutant showed a prolonged effective pollination period with higher seed sets, possibly because of the delayed stigmatic senescence when Exo84c regulated autophagy is blocked. In conclusion, our studies reveal a link between the exocyst complex and the ER network in regulating the degradation of exocytosis vesicles, a process that is essential for normal papilla cell senescence and flower receptivity.

Citation

Zhang, T., Li, Y., Li, C., Zang, J., Gao, E., Kroon, J. T., …Wang, P. (2023). Exo84c interacts with VAP27 to regulate exocytotic compartment degradation and stigma senescence. Nature Communications, 14(1), Article 4888. https://doi.org/10.1038/s41467-023-40729-5

• Journal Article Type: Article
• Acceptance Date: Aug 8, 2023
• Online Publication Date: Aug 14, 2023
• Publication Date: 2023
• Deposit Date: Aug 23, 2023
• Publicly Available Date: Aug 23, 2023
• Journal: Nature Communications
• Publisher: Nature Research
• Peer Reviewed: Peer Reviewed
• Volume: 14
• Issue: 1
• Article Number: 4888
• DOI: https://doi.org/10.1038/s41467-023-40729-5
• Public URL: https://durham-repository.worktribe.com/output/1723778