Interactions of ubiquitin and CHMP5 with the V domain of HD-PTP reveals role for regulation of Vps4 ATPase

Mol Biol Cell. 2021 Dec 1;32(22):ar42. doi: 10.1091/mbc.E21-04-0219. Epub 2021 Sep 29.

Abstract

The family of Bro1 proteins coordinates the activity of the Endosomal Sorting Complexes Required for Transport (ESCRTs) to mediate a number of membrane remodeling events. These events culminate in membrane scission catalyzed by ESCRT-III, whose polymerization and disassembly is controlled by the AAA-ATPase, Vps4. Bro1-family members Alix and HD-PTP as well as yeast Bro1 have central "V" domains that noncovalently bind Ub and connect ubiquitinated proteins to ESCRT-driven functions such as the incorporation of ubiquitinated membrane proteins into intralumenal vesicles of multivesicular bodies. Recently, it was discovered that the V domain of yeast Bro1 binds the MIT domain of Vps4 to stimulate its ATPase activity. Here we determine the structural basis for how the V domain of human HD-PTP binds ubiquitin. The HD-PTP V domain also binds the MIT domain of Vps4, and ubiquitin binding to the HD-PTP V domain enhances its ability to stimulate Vps4 ATPase activity. Additionally, we found that V domains of both HD-PTP and Bro1 bind CHMP5 and Vps60, respectively, providing another potential molecular mechanism to alter Vps4 activity. These data support a model whereby contacts between ubiquitin, ESCRT-III, and Vps4 by V domains of the Bro1 family may coordinate late events in ESCRT-driven membrane remodeling events.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • ATPases Associated with Diverse Cellular Activities / genetics
  • ATPases Associated with Diverse Cellular Activities / metabolism*
  • Binding Sites
  • Endosomal Sorting Complexes Required for Transport / genetics
  • Endosomal Sorting Complexes Required for Transport / metabolism*
  • Humans
  • Models, Molecular
  • Protein Interaction Domains and Motifs
  • Protein Tyrosine Phosphatases, Non-Receptor / chemistry*
  • Protein Tyrosine Phosphatases, Non-Receptor / genetics
  • Protein Tyrosine Phosphatases, Non-Receptor / metabolism*
  • Scattering, Small Angle
  • Two-Hybrid System Techniques
  • Ubiquitin / metabolism*
  • Vacuolar Proton-Translocating ATPases / genetics
  • Vacuolar Proton-Translocating ATPases / metabolism*
  • X-Ray Diffraction

Substances

  • CHMP5 protein, human
  • Endosomal Sorting Complexes Required for Transport
  • Ubiquitin
  • PTPN23 protein, human
  • Protein Tyrosine Phosphatases, Non-Receptor
  • Vacuolar Proton-Translocating ATPases
  • ATPases Associated with Diverse Cellular Activities
  • VPS4A protein, human