Sossin W S, Sweet-Cordero A, Scheller R H
Department of Biological Sciences, Stanford University, CA 94305.
Proc Natl Acad Sci U S A. 1990 Jun;87(12):4845-8. doi: 10.1073/pnas.87.12.4845.
In the bag cells of Aplysia californica, the prohormone of egg-laying hormone is processed by means of endoproteolytic cleavage into two sets of peptides. The amino-terminal region of the prohormone gives rise to the bag cell peptides (alpha, beta, and gamma). These serve an autocrine function; they are autoexcitatory on the bag cells and also act locally to alter the firing patterns of neurons in the abdominal ganglion. The carboxyl-terminal portion of the prohormone gives rise to the egg-laying hormone. This peptide acts as a hormone on nearby neurons and by means of the circulation on peripheral tissues to bring about egg-laying. We have previously reported that the first cleavage of the prohormone, which occurs in the trans-Golgi network, results in two intermediates that are sorted into distinct vesicle classes prior to further processing. Here we show that these distinct vesicles are localized to separate processes, thus spatially segregating autocrine and hormonal release sites. The findings of segregation indicate that neurons need not always release the same set of chemical messengers from all of their endings.
在加州海兔的袋状细胞中，产卵激素的前体激素通过内切蛋白水解切割加工成两组肽。前体激素的氨基末端区域产生袋状细胞肽（α、β和γ）。这些肽具有自分泌功能；它们对袋状细胞具有自激活性，并且还在局部起作用以改变腹神经节中神经元的放电模式。前体激素的羧基末端部分产生产卵激素。这种肽作为一种激素作用于附近的神经元，并通过循环作用于外周组织以引发产卵。我们之前报道过，前体激素在反式高尔基体网络中发生的首次切割产生两种中间体，这两种中间体在进一步加工之前被分选到不同的囊泡类别中。在这里我们表明，这些不同的囊泡定位于不同的突起，从而在空间上分隔自分泌和激素释放位点。分离的结果表明，神经元不一定总是从其所有末梢释放同一组化学信使。
