title: SNAP-23 is not essential for constitutive exocytosis in HeLa cells.
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.
authors.affiliation: Department of Orthodontics, School of Dentistry, Health Sciences University of Hokkaido, Tobetsu, Hokkaido 061-0293, Japan.
authors.forename: Miki
authors.initials: M
authors.lastname: Okayama
authors.forename: Toshiya
authors.initials: T
authors.lastname: Arakawa
authors.forename: Itaru
authors.initials: I
authors.lastname: Mizoguchi
authors.forename: Yoshifumi
authors.initials: Y
authors.lastname: Tajima
authors.forename: Taishin
authors.initials: T
authors.lastname: Takuma
mesh_terms: D000469:Alkaline Phosphatase / Q000378:metabolism; D005089:Exocytosis; D005786:Gene Expression Regulation; D006367:HeLa Cells; D006801:Humans; D050765:Qa-SNARE Proteins / Q000235:genetics / Q000378:metabolism; D050766:Qb-SNARE Proteins / Q000235:genetics / Q000378:metabolism*; D050767:Qc-SNARE Proteins / Q000235:genetics / Q000378:metabolism*; D034741:RNA, Small Interfering / Q000235:genetics