Structure and transport mechanism of P5B-ATPases

Nat Commun. 2021 Jun 25;12(1):3973. doi: 10.1038/s41467-021-24148-y.

Abstract

In human cells, P5B-ATPases execute the active export of physiologically important polyamines such as spermine from lysosomes to the cytosol, a function linked to a palette of disorders. Yet, the overall shape of P5B-ATPases and the mechanisms of polyamine recognition, uptake and transport remain elusive. Here we describe a series of cryo-electron microscopy structures of a yeast homolog of human ATP13A2-5, Ypk9, determined at resolutions reaching 3.4 Å, and depicting three separate transport cycle intermediates, including spermine-bound conformations. Surprisingly, in the absence of cargo, Ypk9 rests in a phosphorylated conformation auto-inhibited by the N-terminus. Spermine uptake is accomplished through an electronegative cleft lined by transmembrane segments 2, 4 and 6. Despite the dramatically different nature of the transported cargo, these findings pinpoint shared principles of transport and regulation among the evolutionary related P4-, P5A- and P5B-ATPases. The data also provide a framework for analysis of associated maladies, such as Parkinson's disease.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Biological Transport
  • Chaetomium / chemistry
  • Cryoelectron Microscopy
  • Fungal Proteins / chemistry
  • Fungal Proteins / genetics
  • Fungal Proteins / metabolism
  • Models, Molecular
  • Phosphorylation
  • Protein Conformation
  • Proton-Translocating ATPases / chemistry*
  • Proton-Translocating ATPases / genetics
  • Proton-Translocating ATPases / metabolism*
  • Spermine / metabolism*

Substances

  • Fungal Proteins
  • Spermine
  • Proton-Translocating ATPases

Supplementary concepts

  • Chaetomium thermophilum