Intracellular trafficking of Niemann-Pick C proteins 1 and 2: obligate components of subcellular lipid transport

Biochim Biophys Acta. 2004 Oct 11;1685(1-3):22-7. doi: 10.1016/j.bbalip.2004.08.008.


Niemann-Pick C 1 (NPC1) is a large integral membrane glycoprotein that resides in late endosomes, whereas NPC2 is a small soluble protein found in the lumen of lysosomes. Mutations in either NPC1 or NPC2 result in aberrant lipid transport from endocytic compartments, which results in lysosomal storage of a complex mixture of lipids, primarily cholesterol and glycosphingolipids. What are the biological functions of the NPC1 and NPC2 proteins? Here we review what is known about the intracellular itinerary of these two proteins as they facilitate lipid transport. We propose that the intracellular trafficking patterns of these proteins will provide clues about their function.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.
  • Review

MeSH terms

  • Animals
  • Carrier Proteins / metabolism*
  • Endosomes / metabolism
  • Glycoproteins / metabolism*
  • Humans
  • Lipid Metabolism*
  • Lysosomes / metabolism
  • Membrane Glycoproteins / metabolism*
  • Models, Biological
  • Niemann-Pick Diseases / metabolism*
  • Protein Transport


  • Carrier Proteins
  • Glycoproteins
  • Membrane Glycoproteins
  • NPC1 protein, human
  • NPC2 protein, human