Integration of two RAB5 groups during endosomal transport in plants.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 29749929.
- Also identified by DOI 10.7554/eLife.34064 and PMC identifier 5947987.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
RAB5 is a key regulator of endosomal functions in eukaryotic cells. Plants possess two different RAB5 groups, canonical and plant-unique types, which act via unknown counteracting mechanisms. Here, we identified an effector molecule of the plant-unique RAB5 in <i>Arabidopsis thaliana</i>, ARA6, which we designated PLANT-UNIQUE RAB5 EFFECTOR 2 (PUF2). Preferential colocalization with canonical RAB5 on endosomes and genetic interaction analysis indicated that PUF2 coordinates vacuolar transport with canonical RAB5, although PUF2 was identified as an effector of ARA6. Competitive binding of PUF2 with GTP-bound ARA6 and GDP-bound canonical RAB5, together interacting with the shared activating factor VPS9a, showed that ARA6 negatively regulates canonical RAB5-mediated vacuolar transport by titrating PUF2 and VPS9a. These results suggest a unique and unprecedented function for a RAB effector involving the integration of two RAB groups to orchestrate endosomal trafficking in plant cells.
Medical subject headings
- Arabidopsis
- Arabidopsis Proteins
- Endosomes
- Guanine Nucleotide Exchange Factors
- rab GTP-Binding Proteins
- rab5 GTP-Binding Proteins