title: Single-molecule analysis of a molecular disassemblase reveals the mechanism of Hsc70-driven clathrin uncoating.
abstract: Heat shock cognate protein-70 (Hsc70) supports remodeling of protein complexes, such as disassembly of clathrin coats on endocytic coated vesicles. To understand how a simple ATP-driven molecular clamp catalyzes a large-scale disassembly reaction, we have used single-particle fluorescence imaging to track the dynamics of Hsc70 and its clathrin substrate in real time. Hsc70 accumulates to a critical level, determined by kinetic modeling to be one Hsc70 for every two functional attachment sites; rapid, all-or-none uncoating then ensues. We propose that Hsc70 traps conformational distortions, seen previously by cryo-EM, in the vicinity of each occupied site and that accumulation of local strains destabilizes the clathrin lattice. Capture of conformational fluctuations may be a general mechanism for chaperone-driven disassembly of protein complexes.
authors.affiliation: Immune Disease Institute, Harvard Medical School, Boston, MA, USA.
authors.forename: Till
authors.initials: T
authors.lastname: Böcking
authors.forename: François
authors.initials: F
authors.lastname: Aguet
authors.forename: Stephen C
authors.initials: SC
authors.lastname: Harrison
authors.forename: Tomas
authors.initials: T
authors.lastname: Kirchhausen
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D034021:Auxilins / Q000378:metabolism; D001665:Binding Sites; D002417:Cattle; D002966:Clathrin / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D022163:Clathrin-Coated Vesicles / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D004926:Escherichia coli / Q000235:genetics; D005453:Fluorescence; D015870:Gene Expression; D050883:HSC70 Heat-Shock Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D007313:Insecta / Q000166:cytology; D007700:Kinetics; D008958:Models, Molecular; D009154:Mutation; D051381:Rats
chemical_list: D034021:Auxilins; D002966:Clathrin; D050883:HSC70 Heat-Shock Proteins; D000255:Adenosine Triphosphate