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The endocytic TPLATE complex internalizes ubiquitinated plasma membrane cargo
Peter Grones1,2, Andreas De Meyer3,4, Roman Pleskot5
1Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium. peter.grones@psb.vib-ugent.be.
Nature Plants
|December 1, 2022
Summary
The TPLATE complex (TPC) subunit TASH3 recognizes ubiquitinated cargo, initiating plant endocytosis. Disrupting this recognition reduces cargo internalization and alters protein trafficking.
Area of Science:
- Plant cell biology
- Molecular plant science
- Membrane trafficking
Background:
- Endocytosis regulates cellular responses by controlling plasma membrane protein levels.
- Clathrin-mediated endocytosis in plants utilizes AP-2 and the TPLATE complex (TPC).
- Ubiquitination targets proteins for endocytosis, but the recognition mechanism is unclear.
Purpose of the Study:
- To investigate the role of the TPLATE complex (TPC) in recognizing ubiquitinated cargo during plant endocytosis.
- To identify the specific TPC subunit involved in ubiquitinated cargo recognition.
Main Methods:
- Investigated the function of TASH3, a TPC subunit, using genetic modification.
- Analyzed plant endocytic densities and flux.
- Performed comparative plasma membrane proteomics to identify ubiquitinated cargo proteins.
Main Results:
- TASH3's SH3 domain-containing appendage directly recognizes ubiquitinated cargo at the plasma membrane.
- TASH3 mutants lacking this appendage formed TPC but exhibited significantly reduced endocytic densities and flux.
- Proteomics revealed altered trafficking of multiple ubiquitinated cargo proteins in TASH3 mutants.
Conclusions:
- The TPLATE complex (TPC), via TASH3, is crucial for the internalization of ubiquitinated cargo in plants.
- This mechanism allows for the regulation of protein trafficking in response to various stimuli and stress conditions.
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