Cleves A E, Cooper D N, Barondes S H, Kelly R B
Department of Biochemistry and Biophysics, University of California, San Francisco, 94143-0534, USA.
J Cell Biol. 1996 Jun;133(5):1017-26. doi: 10.1083/jcb.133.5.1017.
Several physiologically important proteins lack a classical secretory signal sequence, yet they are secreted from cells. To investigate the secretion mechanism of such proteins, a representative mammalian protein that is exported by a nonclassical mechanism, galectin-1, has been expressed in yeast. Galectin-1 is exported across the yeast plasma membrane, and this export does not require the classical secretory pathway nor the yeast multidrug resistance-like protein Ste6p, the transporter for the peptide a factor. A screen for components of the export machinery has identified genes that are involved in nonclassical export. These findings demonstrate a new pathway for protein export that is distinct from the classical secretory pathway in yeast.
几种具有重要生理功能的蛋白质缺乏典型的分泌信号序列，但它们仍能从细胞中分泌出来。为了研究这类蛋白质的分泌机制，一种通过非经典机制输出的代表性哺乳动物蛋白质——半乳糖凝集素-1，已在酵母中表达。半乳糖凝集素-1穿过酵母细胞膜输出，这种输出既不需要经典的分泌途径，也不需要酵母多药耐药样蛋白Ste6p（α因子肽的转运蛋白）。对输出机制成分的筛选已鉴定出参与非经典输出的基因。这些发现证明了一种不同于酵母中经典分泌途径的蛋白质输出新途径。
