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Updated: Jul 11, 2026

Analysis of SNARE-mediated Membrane Fusion Using an Enzymatic Cell Fusion Assay
Published on: October 19, 2012
SNAP-23 is not essential for constitutive exocytosis in HeLa cells
Miki Okayama1, Toshiya Arakawa, Itaru Mizoguchi
1Department of Orthodontics, School of Dentistry, Health Sciences University of Hokkaido, Tobetsu, Hokkaido 061-0293, Japan.
Abstract:
We applied the small interfering RNA (siRNA) technique and over-expression of a dominant-negative mutant to evaluate the role of SNAP-23, a non-neuronal isoform of SNAP-25, in constitutive exocytosis from HeLa cells. Although the protein level of SNAP-23 was reduced to less than 10% of the control value by siRNA directed against SNAP-23, exocytosis of SEAP (secreted alkaline phosphatase) was normal. Double knockdown of SNAP-23 and syntaxin-4 also failed to inhibit the secretion. Furthermore, over-expression of deltaC8-SNAP-23, a dominant-negative mutant of SNAP-23, did not abrogate SEAP secretion. These results suggest that SNAP-23 is not essential for constitutive exocytosis of SEAP.
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