Chua Christelle En Lin, Tang Bor Luen
Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.
Mol Membr Biol. 2008 Jan;25(1):35-45. doi: 10.1080/09687680701504649.
Polarized membrane traffic to different domains of the neuron is well documented, and is required for both establishment and maintenance of neuronal polarity. Some soluble N-ethylmaleimide sensitive factor attachment protein receptor (SNARE) proteins, particularly syntaxin 12/13 and TI-VAMP/VAMP7, have known roles in the neuron. We report here that the brain-enriched SNARE syntaxin 16 (Syn 16) is specifically enriched in neuronal dendrites and found at Golgi outposts, thus confirming that Golgi outposts are endowed with a trans-Golgi network (TGN) component. Over-expression of wild type syntaxin 16 moderately stimulates, whereas that of an N-terminal deletion mutant (Syn 16-DeltaNt) inhibits, neurite outgrowth in both mouse Neuro-2a cells and primary cortical neurons. Consistent with an inhibited neurite growth, cells over-expressing Syn 16-DeltaNt have diminished betaIII-tubulin and F-actin labeling. RNA interference-mediated silencing of syntaxin 16 in primary cortical neurons significantly retards neurite outgrowth. Syntaxin 16 may thus play a role in neurite outgrowth and perhaps other specific dendritic anterograde/retrograde traffic.
极化的膜转运至神经元的不同区域已有充分记载,且对于神经元极性的建立和维持均是必需的。一些可溶性N - 乙基马来酰亚胺敏感因子附着蛋白受体(SNARE)蛋白,尤其是 syntaxin 12/13 和 TI - VAMP/VAMP7,在神经元中具有已知作用。我们在此报告,大脑富集的SNARE蛋白 syntaxin 16(Syn 16)特异性富集于神经元树突,并存在于高尔基体前哨中,从而证实高尔基体前哨具有反式高尔基体网络(TGN)成分。野生型 syntaxin 16 的过表达适度刺激,而 N 端缺失突变体(Syn 16 - DeltaNt)的过表达则抑制小鼠 Neuro - 2a 细胞和原代皮质神经元中的神经突生长。与神经突生长受抑制一致,过表达 Syn 16 - DeltaNt 的细胞中βIII - 微管蛋白和 F - 肌动蛋白标记减少。RNA干扰介导的原代皮质神经元中 syntaxin 16 的沉默显著延缓神经突生长。因此,syntaxin 16 可能在神经突生长以及或许其他特定的树突顺行/逆行转运中发挥作用。