Syntaxin 13 is an integral membrane protein that belongs to the t-SNARE family, a group of proteins involved in protein transport. Confocal immunofluoresence and electron microscopy studies have shown that syntaxin 13 is primarily localized to tubular early and recycling endosomes, where it colocalizes with transferrin receptor, and it is also localized in endosomal vacuoles. Syntaxin 13 has been found to be expressed in all tissues, with higher levels of the protein found in brain, lung, spleen, thymus and testes. Immunoprecipitation studies show that syntaxin 13 complexes with beta-SNAP, VAMP2/3, and SNAP25. The binding of this complex to alpha-SNAP and NSF is terminated in the presence of ATP. These results suggest that syntaxin 13 is a SNARE protein which mediates the recycling protein flow through tubulo vesicular recycling endosomes.