title: Essential N-terminal insertion motif anchors the ESCRT-III filament during MVB vesicle formation.
abstract: The endosomal sorting complexes required for transport (ESCRTs) have emerged as key cellular machinery that drive topologically unique membrane deformation and scission. Understanding how the ESCRT-III polymer interacts with membrane, promoting and/or stabilizing membrane deformation, is an important step in elucidating this sculpting mechanism. Using a combination of genetic and biochemical approaches, both in vivo and in vitro, we identify two essential modules required for ESCRT-III-membrane association: an electrostatic cluster and an N-terminal insertion motif. Mutating either module in yeast causes cargo sorting defects in the MVB pathway. We show that the essential N-terminal insertion motif provides a stable anchor for the ESCRT-III polymer. By replacing this N-terminal motif with well-characterized membrane insertion modules, we demonstrate that the N terminus of Snf7 has been tuned to maintain the topological constraints associated with ESCRT-III-filament-mediated membrane invagination and vesicle formation. Our results provide insights into the spatially unique, ESCRT-III-mediated membrane remodeling.
authors.affiliation: Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY 14853, USA; Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853, USA.
authors.forename: Nicholas J
authors.initials: NJ
authors.lastname: Buchkovich
authors.affiliation: Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY 14853, USA; Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853, USA.
authors.forename: William Mike
authors.initials: WM
authors.lastname: Henne
authors.affiliation: Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY 14853, USA; Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853, USA.
authors.forename: Shaogeng
authors.initials: S
authors.lastname: Tang
authors.affiliation: Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY 14853, USA; Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853, USA. Electronic address: sde26@cornell.edu.
authors.forename: Scott D
authors.initials: SD
authors.lastname: Emr
mesh_terms: D000595:Amino Acid Sequence; D002462:Cell Membrane / Q000378:metabolism*; D056827:Endosomal Sorting Complexes Required for Transport / Q000235:genetics / Q000378:metabolism*; D011992:Endosomes / Q000235:genetics / Q000378:metabolism; D057927:Hydrophobic and Hydrophilic Interactions; D021381:Protein Transport; D012441:Saccharomyces cerevisiae / Q000166:cytology / Q000235:genetics / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism*; D016415:Sequence Alignment; D055672:Static Electricity; D033921:Vesicular Transport Proteins / Q000378:metabolism
chemical_list: D056827:Endosomal Sorting Complexes Required for Transport; C083890:SNF7 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D033921:Vesicular Transport Proteins