A sec1-related vesicle-transport protein that is expressed predominantly in epithelial cells.
Sec1-related proteins are involved in docking and fusion of transport vesicles in eukaryotic cells. Here we report the cloning and molecular characterization of a Sec1-related protein expressed in the MDCK epithelial cell line. This protein represents a canine counterpart of the murine Munc-18-2/Munc-18b/muSec1 protein, displays 93% amino acid identity with these proteins, has a similar tissue mRNA expression pattern, and associates in vitro with syntaxins 1A, 2, and 3. In situ hybridization analysis of embryonic mouse tissues revealed prominent expression of the munc-18-2 mRNA in the epithelia of several tissues. Cell-fractionation studies demonstrated that the majority of Munc-18-2 is membrane associated. Most of the protein is washed off the membranes by sodium carbonate, pH 11. 5. However, the protein is poorly solubilized by detergent treatment. The Munc-18-2 protein was localized, by immunofluorescence microscopy, to the plasma membrane of MDCK cells, and is apically distributed in the epithelial cells of mouse tissues. When overexpressed in COS-1 cells, the protein appeared to be largely cytosolic. However, upon expression with syntaxin 1A, it displayed a shift to the plasma membrane, where the two proteins colocalized. These results identified Munc-18-2 as a predominantly epithelial vesicle-transport protein with a polarized distribution and provided novel in vivo evidence for the association of Sec1-related proteins with members of the syntaxin family.[1]References
- A sec1-related vesicle-transport protein that is expressed predominantly in epithelial cells. Riento, K., Jäntti, J., Jansson, S., Hielm, S., Lehtonen, E., Ehnholm, C., Keränen, S., Olkkonen, V.M. Eur. J. Biochem. (1996) [Pubmed]
Annotations and hyperlinks in this abstract are from individual authors of WikiGenes or automatically generated by the WikiGenes Data Mining Engine. The abstract is from MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.About WikiGenesOpen Access LicencePrivacy PolicyTerms of Useapsburg
