|
General Comment |
Krappa R, et al 1999 reported evectins as vesicular proteins that carry a pleckstrin homology
domain and localize to post-Golgi membranes.
They identified two vesicular proteins, designated evectin (evt)-1 and -2.
These proteins are approximately 25 kDa in molecular mass, lack a cleaved
N-terminal signal sequence, and appear to be inserted into membranes through a
C-terminal hydrophobic anchor. They also carry a pleckstrin homology domain at
their N termini, which potentially couples them to signal transduction pathways
that result in the production of lipid second messengers. evt-1 is specific to the
nervous system, where it is expressed in photoreceptors and myelinating glia,
polarized cell types in which plasma membrane biosynthesis is prodigious and
regulated; in contrast, evt-2 is widely expressed in both neural and nonneural
tissues. In photoreceptors, evt-1 localizes to rhodopsin-bearing membranes of the
post-Golgi, an important transport compartment for which specific molecular
markers have heretofore been lacking. The structure and subcellular distribution
of evt-1 strongly implicate this protein as a mediator of post-Golgi trafficking in
cells that produce large membrane-rich organelles. Its restricted cellular
distribution and genetic locus make it a candidate gene for the inherited human
retinopathy autosomal dominant familial exudative vitreoretinopathy and suggest
that it also may be a susceptibility gene for multiple sclerosis.
|