Sterol carrier protein-2 is involved in cholesterol transfer from the endoplasmic reticulum to the plasma membrane in human fibroblasts

J Biol Chem. 1995 Aug 11;270(32):18723-6. doi: 10.1074/jbc.270.32.18723.

Abstract

The cellular mechanism of cholesterol transport from the endoplasmic reticulum to the plasma membrane is currently unknown. To assess the possibility that sterol carrier protein-2 (SCP-2) is involved in this transport, we studied the time course of newly synthesized cholesterol incorporation in the plasma membrane of normal and SCP-2-deficient (Zellweger syndrome) human fibroblasts. Cholesterol transfer was rapid, cytoskeleton-independent, and Golgi-independent in normal cells, but it was slower, cytoskeleton-dependent, and Golgi-dependent in SCP-2-deficient cells. After SCP-2 antisense oligonucleotides treatment of normal fibroblasts, the rapid transport was reduced by 81% with a simultaneous increase of the slower one. These results suggest that in normal fibroblasts the major fraction of newly synthesized cholesterol is transported to the plasma membrane by a SCP-2-dependent mechanism. In contrast, in SCP-2-deficient cells, newly synthesized cholesterol leaves the endoplasmic reticulum by a cytoskeleton/Golgi-dependent mechanism.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Base Sequence
  • Carrier Proteins / physiology*
  • Cell Membrane / metabolism*
  • Cells, Cultured
  • Cholesterol / metabolism*
  • Colchicine / pharmacology
  • Cytoskeleton / metabolism
  • Endoplasmic Reticulum / metabolism*
  • Fibroblasts / metabolism
  • Golgi Apparatus / metabolism
  • Humans
  • Molecular Sequence Data
  • Oligonucleotides, Antisense / pharmacology
  • Plant Proteins*

Substances

  • Carrier Proteins
  • Oligonucleotides, Antisense
  • Plant Proteins
  • sterol carrier proteins
  • Cholesterol
  • Colchicine