Virmani Tuhin, Han Weiping, Liu Xinran, Südhof Thomas C, Kavalali Ege T
Center for Basic Neuroscience, Department of Molecular Genetics, The University of Texas Southwestern Medical Center, Dallas, TX 75390-9111, USA.
EMBO J. 2003 Oct 15;22(20):5347-57. doi: 10.1093/emboj/cdg514.
The speed of synaptic vesicle recycling determines the efficacy of neurotransmission during repetitive stimulation. Synaptotagmins are synaptic C(2)-domain proteins that are involved in exocytosis, but have also been linked to endocytosis. We now demonstrate that upon expression in transfected neurons, a short splice variant of synaptotagmin 7 that lacks C(2)-domains accelerates endocytic recycling of synaptic vesicles, whereas a longer splice variant that contains C(2)-domains decelerates recycling. These results suggest that alternative splicing of synaptotagmin 7 acts as a molecular switch, which targets vesicles to fast and slow recycling pathways.
突触小泡循环的速度决定了重复刺激期间神经传递的效率。突触结合蛋白是参与胞吐作用的突触C2结构域蛋白，但也与胞吞作用有关。我们现在证明，在转染神经元中表达时，缺乏C2结构域的突触结合蛋白7的短剪接变体加速了突触小泡的内吞循环，而含有C2结构域的较长剪接变体则减缓了循环。这些结果表明，突触结合蛋白7的可变剪接充当分子开关，将小泡靶向快速和慢速循环途径。
