title: The Arabidopsis deubiquitinating enzyme AMSH3 interacts with ESCRT-III subunits and regulates their localization.
abstract: Ubiquitination and deubiquitination regulate various cellular processes. We have recently shown that the deubiquitinating enzyme Associated Molecule with the SH3 domain of STAM3 (AMSH3) is involved in vacuole biogenesis and intracellular trafficking in Arabidopsis thaliana. However, little is known about the identity of its interaction partners and deubiquitination substrates. Here, we provide evidence that AMSH3 interacts with ESCRT-III subunits VPS2.1 and VPS24.1. The interaction of ESCRT-III subunits with AMSH3 is mediated by the MIM1 domain and depends on the MIT domain of AMSH3. We further show that AMSH3, VPS2.1, and VPS24.1 localize to class E compartments when ESCRT-III disassembly is inhibited by coexpression of inactive Suppressor of K+ transport Defect 1 (SKD1), an AAA-ATPase involved in the disassembly of ESCRT-III. We also provide evidence that AMSH3 and SKD1 compete for binding to VPS2.1. Furthermore, we show that the loss of AMSH3 enzymatic activity leads to the formation of cellular compartments that contain AMSH3, VPS2.1, and VPS24.1. Taken together, our study presents evidence that AMSH3 interacts with classical core ESCRT-III components and thereby provides a molecular framework for the function of AMSH3 in plants.
authors.affiliation: Department of Plant Systems Biology, Technische Universität München, 85354 Freising, Germany.
authors.forename: Anthi
authors.initials: A
authors.lastname: Katsiarimpa
authors.forename: Franziska
authors.initials: F
authors.lastname: Anzenberger
authors.forename: Nicole
authors.initials: N
authors.lastname: Schlager
authors.forename: Susanne
authors.initials: S
authors.lastname: Neubert
authors.forename: Marie-Theres
authors.initials: MT
authors.lastname: Hauser
authors.forename: Claus
authors.initials: C
authors.lastname: Schwechheimer
authors.forename: Erika
authors.initials: E
authors.lastname: Isono
mesh_terms: D000251:Adenosine Triphosphatases / Q000235:genetics / Q000378:metabolism; D017360:Arabidopsis / Q000201:enzymology* / Q000235:genetics / Q000378:metabolism / Q000648:ultrastructure; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D016384:Consensus Sequence; D056827:Endosomal Sorting Complexes Required for Transport / Q000235:genetics / Q000378:metabolism*; D011992:Endosomes / Q000201:enzymology* / Q000378:metabolism / Q000648:ultrastructure; D035264:Flowers / Q000201:enzymology / Q000235:genetics / Q000378:metabolism / Q000648:ultrastructure; D015723:Gene Library; D016254:Mutagenesis, Insertional; D010802:Phylogeny; D030821:Plants, Genetically Modified; D011485:Protein Binding; D054730:Protein Interaction Domains and Motifs; D025941:Protein Interaction Mapping; D021381:Protein Transport; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism; D036226:Seedlings / Q000201:enzymology / Q000235:genetics / Q000378:metabolism / Q000648:ultrastructure; D016415:Sequence Alignment; D054875:Ubiquitination; D014617:Vacuoles / Q000201:enzymology / Q000378:metabolism
chemical_list: D029681:Arabidopsis Proteins; D056827:Endosomal Sorting Complexes Required for Transport; D029701:Saccharomyces cerevisiae Proteins; C576222:VPS2.1 protein, Arabidopsis; C576223:VPS24.1 protein, Arabidopsis; D000251:Adenosine Triphosphatases; C560560:SKD1 protein, Arabidopsis