Wächter Andrea, Schwappach Blanche
Zentrum für Molekulare Biologie (ZMBH), Universität Heidelberg, Im Neuenheimer Feld 282, D-69120 Heidelberg, Germany.
FEBS Lett. 2005 Feb 14;579(5):1149-53. doi: 10.1016/j.febslet.2005.01.011.
CLC chloride channels are a family of channel proteins mediating chloride transport across the plasma membrane and intracellular membranes. The single yeast CLC protein Gef1p is localized to the Golgi and endosomal system. Investigating epitope-tagged variants of Gef1p, we found that the channel is proteolytically processed in the secretory pathway. Proteolytic cleavage occurs in the first extracellular loop of the protein at residues KR136/137 and is carried out by the Kex2p protease. Fragments mimicking the N- and C-terminal products of the cleavage reaction are non-functional when expressed alone. However, functional channels can assemble when the two fragments are co-expressed.
CLC氯离子通道是一类介导氯离子跨质膜和细胞内膜运输的通道蛋白。酵母中的单个CLC蛋白Gef1p定位于高尔基体和内体系统。通过研究Gef1p的表位标记变体，我们发现该通道在分泌途径中会发生蛋白水解加工。蛋白水解切割发生在该蛋白的第一个细胞外环中的KR136/137残基处，由Kex2p蛋白酶进行。单独表达时，模拟切割反应的N端和C端产物的片段无功能。然而，当这两个片段共表达时，可以组装成功能性通道。
