We have reexamined the intracellular localization of the ubiquitously expressed target membrane SNAP receptor (t-SNARE), SNAP-23. While SNAP-23 appears on the plasma membrane, in the cell types examined there is a significant pool associated with endosomal compartments. Immune-staining and expression of green fluorescent protein-tagged SNAP-23, show that it has a punctate, perinuclear localization in HepG2 and HT4 cells. This distribution overlaps significantly with transferrin receptor and slightly with the late endosome/lysosomal protein LAMP-1. The localization of SNAP-23 changes as HepG2 cells polarize. Initially it is concentrated at sites of cell-cell contact and then almost exclusively to the apical (or bile canalicular) domain of the cell. These data are consistent with a role for SNAP-23 in both endosome-plasma membrane trafficking as well as endosome-endosome transport.
|Number of pages||7|
|Journal||Biochemical and Biophysical Research Communications|
|State||Published - Feb 16 1999|
Bibliographical noteFunding Information:
We thank the members of the Whiteheart Laboratory: Audrey Bernstein, Paula Lemons, Elena Matveeva, Ping He, Tara Rutledge, Kris Jones, Todd Schraw, and Susan Buhrow for their helpful comments on this manuscript. This work is supported by a grant from the National Institutes of Health to S.W.W.
- Membrane trafficking
ASJC Scopus subject areas
- Molecular Biology
- Cell Biology