Enables protein domain specific binding activity. Predicted to be involved in several processes, including endoplasmic reticulum membrane organization; positive regulation of ER to Golgi vesicle-mediated transport; and regulation of organelle organization. Predicted to act upstream of or within protein transport and vesicle-mediated transport. Predicted to be located in Golgi apparatus and membrane. Predicted to be integral component of membrane. Predicted to be part of SNARE complex. Predicted to be active in endoplasmic reticulum. Is expressed in several structures, including alimentary system; brain; genitourinary system; hemolymphoid system gland; and limb. Orthologous to human STX18 (syntaxin 18). [provided by Alliance of Genome Resources, Apr 2022]