Vps4 disassembles an ESCRT-III filament by global unfolding and processive translocation.
The AAA+ ATPase Vps4 disassembles ESCRT-III and is essential for HIV-1 budding and other pathways. Vps4 is a paradigmatic member of a class of hexameric AAA+ ATPases that disassemble protein complexes without degradation. To distinguish between local displacement versus global unfolding mechanisms for complex disassembly, we carried out hydrogen/deuterium exchange during Saccharomyces cerevisiae Vps4 disassembly of a chimeric Vps24-2 ESCRT-III filament. EX1 exchange behavior shows that Vps4 completely unfolds ESCRT-III substrates on a time scale consistent with the disassembly reaction. The established unfoldase ClpX showed the same pattern, thus demonstrating a common unfolding mechanism. Vps4 hexamers containing a single cysteine residue in the pore loops were cross-linked to ESCRT-III subunits containing unique cysteines within the folded core domain. These data support a mechanism in which Vps4 disassembles its substrates by completely unfolding them and threading them through the central pore.
Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, California, USA.
Bei
B
Yang
Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, California, USA.
Goran
0000000248419949
G
Stjepanovic
Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, California, USA.
Qingtao
Q
Shen
Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, California, USA.
Andreas
A
Martin
1] Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, California, USA. [2] Life Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California, USA.
James H
JH
Hurley
D000251:Adenosine Triphosphatases / Q000378:metabolism*; D056827:Endosomal Sorting Complexes Required for Transport / Q000378:metabolism*; D018832:Molecular Chaperones / Q000378:metabolism*; D017510:Protein Folding; D021381:Protein Transport; D012441:Saccharomyces cerevisiae / Q000201:enzymology*; D029701:Saccharomyces cerevisiae Proteins / Q000378:metabolism*
D056827:Endosomal Sorting Complexes Required for Transport; D018832:Molecular Chaperones; D029701:Saccharomyces cerevisiae Proteins; C107528:VPS4 protein, S cerevisiae; C488472:unfolding protein, S cerevisiae; D000251:Adenosine Triphosphatases