A mouse TRAPP-related protein is involved in pigmentation

Genomics. 2006 Aug;88(2):196-203. doi: 10.1016/j.ygeno.2006.04.002. Epub 2006 May 12.


We identified a new spontaneous recessive mutation in the mouse, mhyp (mosaic hypopigmentation), in a screen for novel proviral integration sites in a multiple ecotropic provirus mapping stock. Integration of an 8.4-kb retrovirus results in mosaic loss of coat pigment in mhyp homozygotes. Patchy loss of pigmentation in the retinal pigmented epithelial layer of the eye with abnormal melanosomes is also evident. We mapped mhyp to mouse chromosome 7 and cloned the underlying gene. mhyp is a defect in the Trappc6a gene. Expression of Trappc6a is markedly diminished in mhyp homozygotes. The normal protein, TRAPPC6A, is a subunit of the TRAPP (transport protein particle) I and II complexes. While TRAPP complexes are essential for ER-to-Golgi and intra-Golgi vesicle trafficking in yeast, TRAPP subunits participate in additional, including post-Golgi, transport events in mammals. The data implicate mammalian TRAPPC6A in vesicle trafficking during melanosome biogenesis.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Chromosome Mapping
  • Cloning, Molecular
  • DNA / metabolism
  • Hair Color* / genetics
  • Membrane Proteins / genetics*
  • Methylation
  • Mice
  • Mice, Congenic
  • Mice, Inbred C57BL
  • Microscopy, Electron, Transmission
  • Molecular Sequence Data
  • Mutation
  • Protein Subunits / genetics
  • RNA / metabolism
  • Sequence Alignment
  • Vesicular Transport Proteins / chemistry
  • Vesicular Transport Proteins / genetics*
  • Vesicular Transport Proteins / metabolism


  • Membrane Proteins
  • Protein Subunits
  • TRAPPC6A protein, mouse
  • Vesicular Transport Proteins
  • transport protein particle, TRAPP
  • RNA
  • DNA