Okayama Miki, Arakawa Toshiya, Mizoguchi Itaru, Tajima Yoshifumi, Takuma Taishin
Department of Orthodontics, School of Dentistry, Health Sciences University of Hokkaido, Tobetsu, Hokkaido 061-0293, Japan.
FEBS Lett. 2007 Oct 2;581(24):4583-8. doi: 10.1016/j.febslet.2007.08.046. Epub 2007 Aug 31.
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.
我们应用小干扰RNA（siRNA）技术和显性负性突变体的过表达来评估SNAP-25的非神经元亚型SNAP-23在HeLa细胞组成型胞吐作用中的作用。尽管针对SNAP-23的siRNA将SNAP-23的蛋白水平降低至对照值的10%以下，但分泌型碱性磷酸酶（SEAP）的胞吐作用正常。对SNAP-23和 syntaxin-4的双重敲低也未能抑制分泌。此外，SNAP-23的显性负性突变体deltaC8-SNAP-23的过表达并未消除SEAP的分泌。这些结果表明，SNAP-23对于SEAP的组成型胞吐作用并非必不可少。
