Lowe Martin, Lane Jon D, Woodman Philip G, Allan Victoria J
School of Biological Sciences, University of Manchester, 2.205 Stopford Building, Oxford Road, Manchester, M13 9PT, UK.
J Cell Sci. 2004 Mar 1;117(Pt 7):1139-50. doi: 10.1242/jcs.00950. Epub 2004 Feb 17.
We report the caspase-dependent cleavage of two Golgi-associated transport factors during apoptosis. The tethering factor giantin is rapidly cleaved both in vitro and in vivo at a conserved site, to generate a stable membrane-anchored domain and a soluble domain that is subject to further caspase-dependent cleavage. The t-SNARE syntaxin 5 is also cleaved rapidly, resulting in the separation of the catalytic membrane-proximal domain from an N-terminal regulatory domain. Cleavage of giantin and syntaxin 5 is accompanied by a cessation of vesicular transport between the ER and the Golgi complex, which first manifests itself as a block in ER exit. The contribution that such an inhibition of trafficking may make towards the generation of an apoptotic phenotype is discussed.
我们报道了凋亡过程中两个高尔基体相关转运因子的半胱天冬酶依赖性切割。拴系因子巨蛋白在体外和体内均在一个保守位点迅速被切割，产生一个稳定的膜锚定结构域和一个可溶结构域，该可溶结构域会进一步发生半胱天冬酶依赖性切割。t-SNARE syntaxin 5也迅速被切割，导致催化性膜近端结构域与N端调节结构域分离。巨蛋白和syntaxin 5的切割伴随着内质网和高尔基体复合体之间囊泡运输的停止，这首先表现为内质网出口受阻。本文讨论了这种运输抑制对凋亡表型产生的作用。
