Background of the antigen
In eukaryotic cells, the Golgi apparatus receives newly synthesized proteins from the endoplasmic reticulum (ER) and, after covalent modification, delivers them to their destination in the cell. For membrane-directed proteins this process is believed to be carried out via vesicular transport. Correct vesicular transport is determined by specific pairing of vesicle-associated SNAREs (v-SNAREs) with those on the target membrane (t-SNAREs). Unconventional SNARE in the ER 1, also known as USE1 or protein p31, is a 259 amino acid t-SNARE that forms a larger complex with ZW10, RINT-1 and Syntaxin 18. Upon Mg2+-AP treatment in the presence of NSF and ?SNAP, ZW10, RINT-1 and USE1 dissociate from Syntaxin 18. USE1 is a single-pass type IV membrane protein that is localized to the endoplasmic reticulum membrane. Three named isoforms exist for USE1 as a result of alternative splicing events.
