Endocytosis of the damage-associated molecular pattern receptor PEPR1 is BAK1-dependent.

Claus, L. A. N.; Ortiz-Morea, F. A.; Yang, S.-L.; Yekondi, S.; Yeo, I.-C.; Vanhoutte, I.; Vukasinovic, N.; Ma, Q.; De Smet, I.; He, P.; Shan, L.; Russinova, E.

doi:10.1101/2025.03.15.643409

bioRxiv · 10.1101/2025.03.15.643409

Endocytosis of the damage-associated molecular pattern receptor PEPR1 is BAK1-dependent.

Claus, L. A. N.·Ortiz-Morea, F. A.·Yang, S.-L.·Yekondi, S.·Yeo, I.-C.·Vanhoutte, I.·Vukasinovic, N.·Ma, Q.·De Smet, I.·He, P.·Shan, L.·Russinova, E.

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Abstract

After cellular damage caused by wounding or pathogens, Arabidopsis thaliana endogenous elicitor peptides (Peps) are released into the apoplast, enhancing innate immunity by directly binding to the membrane-localized leucine-rich repeat receptor kinase PEP RECEPTOR1 (PEPR1). Ligand binding induces PEPR1 heterodimerization with the co-receptor BRASSINOSTEROID INSENSITIVE1-ASSOCIATED KINASE1 (BAK1), followed by PEPR1 internalization, both essential for a subset of Pep1-induced responses. However, the role of BAK1 in Pep1-triggered PEPR1 endocytosis remains unclear. Here, we show that the ligand-induced PEPR1 endocytosis depends on its kinase activity and requires BAK1 C-terminal tail phosphorylation, which is equally indispensable for immune signaling and BAK1 internalization. Using a GFP insertional mutagenesis approach, we generated a partially functional GFP-tagged BAK1 to demonstrate that, following Pep1 elicitation, BAK1 and PEPR1 are endocytosed together with similar dynamics. Our findings identify the BAK1 function as a prerequisite for PEPR1 internalization.

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Claus, L. A. N., Ortiz-Morea, F. A., Yang, S.-L., Yekondi, S., Yeo, I.-C., Vanhoutte, I., Vukasinovic, N., Ma, Q., De Smet, I., He, P., Shan, L., Russinova, E.. 2025-03-17. Endocytosis of the damage-associated molecular pattern receptor PEPR1 is BAK1-dependent.. https://doi.org/10.1101/2025.03.15.643409

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