SDPR induces membrane curvature and functions in the formation of caveolae

Nat Cell Biol. 2009 Jul;11(7):807-14. doi: 10.1038/ncb1887. Epub 2009 Jun 14.

Abstract

Caveolae are plasma membrane invaginations with a characteristic flask-shaped morphology. They function in diverse cellular processes, including endocytosis. The mechanism by which caveolae are generated is not fully understood, but both caveolin proteins and PTRF (polymerase I and transcript release factor, also known as cavin) are important. Here we show that loss of SDPR (serum deprivation protein response) causes loss of caveolae. SDPR binds directly to PTRF and recruits PTRF to caveolar membranes. Overexpression of SDPR, unlike PTRF, induces deformation of caveolae and extensive tubulation of the plasma membrane. The B-subunit of Shiga toxin (STB) also induces membrane tubulation and these membrane tubes also originate from caveolae. STB colocalizes extensively with both SDPR and caveolin 1. Loss of caveolae reduces the propensity of STB to induce membrane tubulation. We conclude that SDPR is a membrane-curvature-inducing component of caveolae, and that STB-induced membrane tubulation is facilitated by caveolae.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Blotting, Western
  • Carrier Proteins / genetics
  • Carrier Proteins / metabolism
  • Carrier Proteins / physiology*
  • Caveolae / metabolism*
  • Caveolae / ultrastructure
  • Caveolin 1 / metabolism
  • Cell Membrane / metabolism*
  • Cell Membrane / ultrastructure
  • Cryoelectron Microscopy
  • Fluorescent Antibody Technique, Indirect
  • HeLa Cells
  • Humans
  • Immunoprecipitation
  • Microscopy
  • Microscopy, Electron, Transmission
  • Phosphate-Binding Proteins
  • Protein Binding / genetics
  • Protein Binding / physiology
  • Protein Transport / genetics
  • Protein Transport / physiology
  • RNA, Small Interfering
  • RNA-Binding Proteins / metabolism
  • Rats

Substances

  • CAVIN2 protein, human
  • Carrier Proteins
  • Caveolin 1
  • Phosphate-Binding Proteins
  • RNA, Small Interfering
  • RNA-Binding Proteins