The ESCRT-III-interacting deubiquitinating enzyme AMSH3 is essential for degradation of ubiquitinated membrane proteins in Arabidopsis thaliana.
Post-translational modification by ubiquitin plays a key role in the regulation of endocytic degradation in which ubiquitinated plasma membrane cargos are transported to the vacuole for degradation dependent on the ESCRT (endosomal sorting complex required for transport) machinery. Arabidopsis AMSH3 (ASSOCIATED MOLECULE WITH THE SH3 DOMAIN OF STAM 3) is a deubiquitinating enzyme that interacts with at least two subunits of the ESCRT-III machinery, VPS2.1 and VPS24.1. amsh3 null mutation causes seedling lethality, and amsh3 null mutants show defects in multiple intracellular trafficking pathways. In this study, we further analyzed the amsh3 mutant phenotype and showed that amsh3 accumulates membrane-associated ubiquitinated proteins, supporting the indication that AMSH3 functions in ubiquitin-mediated endocytic degradation. In accordance with this, an enzymatic inactive variant of AMSH3 inhibits the AvrPtoB-dependent endocytic degradation of CERK1 (CHITIN ELICITOR RECEPTOR KINASE 1). Furthermore, we showed that the interaction of AMSH3 with ESCRT-III is important for its function in planta. Together, our data indicate the importance of AMSH3 and the AMSH3-ESCRT-III interaction for deubiquitination and degradation of ubiquitinated membrane substrates in plants.
Department of Plant Systems Biology, Technische Universität München, D-85354,Freising, Germany.
Anthi
A
Katsiarimpa
Alfonso
A
Muñoz
Kamila
K
Kalinowska
Tomohiro
T
Uemura
Enrique
E
Rojo
Erika
E
Isono
D000730:Androstadienes / Q000494:pharmacology; D017360:Arabidopsis / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000737:chemistry / Q000378:metabolism*; D015415:Biomarkers / Q000378:metabolism; D020126:Brefeldin A / Q000494:pharmacology; D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism; D004721:Endoplasmic Reticulum / Q000187:drug effects / Q000378:metabolism; D056827:Endosomal Sorting Complexes Required for Transport / Q000378:metabolism*; D005816:Genetic Complementation Test; D006056:Golgi Apparatus / Q000187:drug effects / Q000378:metabolism; D049452:Green Fluorescent Proteins / Q000378:metabolism; D008565:Membrane Proteins / Q000378:metabolism*; D010641:Phenotype; D011485:Protein Binding / Q000187:drug effects; D055550:Protein Stability / Q000187:drug effects; D017434:Protein Structure, Tertiary; D059748:Proteolysis / Q000187:drug effects; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D013329:Structure-Activity Relationship; D013347:Subcellular Fractions / Q000187:drug effects / Q000378:metabolism; D064570:Ubiquitin-Specific Proteases / Q000737:chemistry / Q000378:metabolism*; D057149:Ubiquitinated Proteins / Q000378:metabolism*; D054875:Ubiquitination / Q000187:drug effects; D014617:Vacuoles / Q000187:drug effects / Q000378:metabolism; D000077191:Wortmannin
D000730:Androstadienes; D029681:Arabidopsis Proteins; D015415:Biomarkers; D056827:Endosomal Sorting Complexes Required for Transport; D008565:Membrane Proteins; D011993:Recombinant Fusion Proteins; D057149:Ubiquitinated Proteins; D049452:Green Fluorescent Proteins; D020126:Brefeldin A; D064570:Ubiquitin-Specific Proteases; C586776:AMSH3 protein, Arabidopsis; D000077191:Wortmannin
AMSH; Arabidopsis thaliana; ESCRT; Ubiquitin