Regulation of endocytosis

Clathrin-mediated endocytosis (CME) is a multiplayer process that needs to be tightly controlled. However, how endocytosis is regulated in plants remains unknown. TPLATE complex (TPC) is an eight-core-component protein, essential for plant growth via its role as major adaptor module for CME. 

Our preliminary evidence shows phosphorylation of the EH subunits of the TPC under multiple developmental, signaling and stress conditions including high and low temperature (1,2,3). Our aim is to investigate how post-translational modifications (PTMs), particularly protein phosphorylation of TPC subunits affects the dynamics of CME and how this is linked to plant development (fig1).

Currently, we are focusing on the EH subunits as modulating their condensate forming properties has been shown to allow the regulation of CME (4).

Therefore, we have teamed up with the group of Ive De Smet (VIB PSB) to investigate AtEH phosphorylation and to uncover how phosphor-regulation affects their condensate forming properties and function. To do this, we are generating various phospho-mutant forms and we are performing mutant rescue experiments under normal conditions as well as under high temperature stress.

Fig1. Overview of the regulation of endocytosis. Preliminary evidence shows phosphorylation of the EH subunits of the TPC under multiple developmental, signaling and stress conditions including high and low temperature.


 

References:

1.TW Kim,. et al. Mapping the signaling network of BIN2 kinase using TurboID-mediated biotin labeling and phosphoproteomics. Plant Cell. 2023 Mar 15;35(3):975-993. doi: 10.1093/plcell/koad013.

2.Vu, L. D,. et al. The membrane-localized protein kinase MAP4K4/TOT3 regulates thermomorphogenesis. Nature communications 12, 2842, doi:10.1038/s41467-021-23112-0 (2021).

3. J Tan ,. et al. Data-Independent Acquisition-Based Proteome and Phosphoproteome Profiling Reveals Early Protein Phosphorylation and Dephosphorylation Events in Arabidopsis Seedlings upon Cold Exposure. Int J Mol Sci. 2021 Nov 27;22(23):12856. doi: 10.3390/ijms222312856.

4. JM Dragwidge ,. et al. Biomolecular condensation orchestrates clathrin-mediated endocytosis in plants. Nat Cell Biol. 2024 Mar;26(3):438-449. doi: 10.1038/s41556-024-01354-6. Epub 2024 Feb 12.