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Expression of SNARE proteins in enteroendocrine cell lines and functional role of tetanus toxin‐sensitive proteins in cholecystokinin release
Author(s) -
Némoz-Gaillard Eric,
Bosshard Arlette,
Regazzi Romano,
Bernard Christine,
Cuber Jean-Claude,
Takahashi Masami,
Catsicas Stefan,
Chayvialle Jean-Alain,
Abello Jacques
Publication year - 1998
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/s0014-5793(98)00209-9
Subject(s) - syntaxin , enteroendocrine cell , microbiology and biotechnology , secretion , cell culture , biology , exocytosis , chemistry , biochemistry , endocrine system , genetics , hormone
In neurons, synaptic vesicle exocytosis involves the formation of a core complex particle including syntaxin‐1, synaptosomal‐associated protein of 25 kDa (SNAP‐25) and vesicle‐associated membrane protein (VAMP)‐2/synaptobrevin. The expression of these proteins was investigated in a panel of cell lines, including lines of endocrine and intestinal origin, by Western blotting and/or immunocytochemistry. The three core complex proteins were detected in the enteroendocrine, cholecystokinin (CCK)‐secreting, cell lines STC‐1 and GLUTag, and in the endocrine non‐intestinal cell lines CA‐77 and HIT‐T15. In contrast, SNAP‐25 and syntaxin‐1 were undetected in the intestinal non‐endocrine cell lines IEC‐6, HT‐29 and Caco‐2, whereas a slight expression of VAMP‐2 was documented in IEC‐6 and HT‐29 cells. Co‐immunoprecipitation experiments indicated that syntaxin‐1, SNAP‐25 and VAMP‐2 were present in a complex similar to that identified in brain. In the STC‐1 cell line, treatment of streptolysin‐O‐permeabilized cells with tetanus toxin (Tetx) selectively cleaved VAMP‐2 and VAMP‐3/cellubrevin, and simultaneously abolished Ca 2+ ‐induced CCK secretion (IC 50 ∼12 nM). These results show that endocrine cell lines of intestinal origin express syntaxin‐1, SNAP‐25 and VAMP‐2, and suggest a key role for a Tetx‐sensitive protein (for example VAMP‐2 and/or VAMP‐3) in the CCK secretion by STC‐1 cells.