STX16 encodes a protein that is a member of the syntaxin or t-SNARE (target-SNAP receptor) family. These proteins are found on cell membranes and serve as the targets for V-SNARES (vesicle-SNAP receptors) permitting specific synaptic vesicle docking and fusion. A microdeletion in the region of chromosome 20 where this gene is located has been associated with pseudohypoparathyroidism type Ib. Multiple transcript variants encoding different isoforms have been found for this gene. The predicted 307-amino acid protein contains the C-terminal hydrophobic tail anchor characteristic of syntaxins, and several potential coiled-coil regions. Using immunofluorescence, the authors determined that an epitope-tagged SYN16 protein localized to the Golgi apparatus.