Dictyostelium Tom1 participates to an ancestral ESCRT-0 complex.
Sorting of ubiquitinated proteins to multivesicular bodies (MVBs) in mammalian cells relies on proteins with a Vps27/Hrs/STAM (VHS) domain. Here, we show that the amoeba Dictyostelium presents only one protein with a VHS domain: DdTom1. We demonstrate that the VHS domain of DdTom1 is followed by a Golgi-localized, gamma-ear-containing, ADP-ribosylation-factor-binding and Tom1 (GAT) domain that binds ubiquitin, and by a non-conserved C-terminal domain that can recruit clathrin, EGFr pathway substrate 15 and tumor susceptibility gene 101, a component of the MVB biogenesis machinery [endosomal complexes required for transport (ESCRT) complexes]. Both VHS and GAT domains interact with phospholipids and therefore could ensure the recruitment of DdTom1 to endosomal membranes. We propose that DdTom1 participates in an ancestral ESCRT-0 complex implicated in the sorting of ubiquitinated proteins into MVBs.
Blanc
Cédric
C
IFR 128 BioSciences Gerland-Lyon Sud, Institut de Biologie et Chimie des Protéines, UMR5086 - CNRS/Université Lyon I, 7 Passage du Vercors, 69367 Lyon cedex 07, France.
Charette
Steve J
SJ
Mattei
Sara
S
Aubry
Laurence
L
Smith
Ewan W
EW
Cosson
Pierre
P
Letourneur
François
F
D033942:Adaptor Proteins, Vesicular Transport / Q000378:metabolism; D020816:Amino Acid Motifs; D000818:Animals; D055252:Cell-Derived Microparticles / Q000378:metabolism*; D002966:Clathrin / Q000378:metabolism; D003593:Cytoplasm / Q000378:metabolism; D004023:Dictyostelium / Q000235:genetics / Q000378:metabolism* / Q000648:ultrastructure; D017353:Gene Deletion; D006801:Humans; D008247:Lysosomes / Q000378:metabolism; D008854:Microscopy, Electron; D011485:Protein Binding; D015800:Protozoan Proteins / Q000235:genetics / Q000378:metabolism*
D033942:Adaptor Proteins, Vesicular Transport; D002966:Clathrin; D015800:Protozoan Proteins