The soluble NSF attachment protein (SNAP) proteins are involved in vesicular transport between the endoplasmic reticulum and Golgi apparatus [1]. They act as adaptors between SNARE (integral membrane SNAP receptor) proteins and NSF (N-ethylmaleimide-sensitive factor) [2]. They are structurally similar to TPR repeats [2].

1: SNAP family of NSF attachment proteins includes a brain-specific isoform. Whiteheart SW, Griff IC, Brunner M, Clary DO, Mayer T, Buhrow SA, Rothman JE; Nature. 1993;362:353-355. PMID:8455721

2: Crystal structure of the vesicular transport protein Sec17: implications for SNAP function in SNARE complex disassembly. Rice LM, Brunger AT; Mol Cell. 1999;4:85-95. PMID:10445030