ADP-RIBOSYLATION FACTOR, A SMALL GTP-BINDING PROTEIN, IS REQUIRED FOR BINDING OF THE COATOMER PROTEIN BETA-COP TO GOLGI MEMBRANES
ADP-RIBOSYLATION FACTOR, A SMALL GTP-BINDING PROTEIN, IS REQUIRED FOR BINDING OF THE COATOMER PROTEIN BETA-COP TO GOLGI MEMBRANES
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DOI：
10.1073/pnas.89.14.6408
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发表时间：
1992-07-15
影响因子：
11.1
通讯作者：
KLAUSNER, RD
中科院分区：
文献类型：
--
作者：
DONALDSON, JG;CASSEL, D;KLAUSNER, RD
外被体是一种与高尔基体膜可逆结合的胞质蛋白复合物，参与调节高尔基体膜转运。β-COP是外被体的一种成分，它与高尔基体膜的结合可以通过鸟苷5 '-[γ-硫代]三磷酸（GTP[γ-S]）（GTP的一种不可水解的类似物）和铝和氟离子的混合物（Al/F）来增强。在这里，我们表明，ADP-核糖基化因子（ARF）是必需的β-COP的结合。因此，从ARF中分离出来的被膜组分中所含的β-COP不与高尔基体膜结合，而结合可以通过加入重组ARF来重建。此外，ARF的N-末端肽，其阻断ARF与高尔基体膜的结合，抑制GTP[γ-S]-以及Al/F-增强的β-COP结合。我们表明，高尔基体外壳蛋白结合涉及一个顺序反应，其中ARF和GTP[γ-S]与膜的初始相互作用允许随后的β-COP结合在没有游离ARF和GTP[γ-S]的情况下发生。真菌代谢物布雷菲德菌素A，这是已知的，以防止与高尔基体膜的外壳蛋白的协会，显示出发挥这种作用，通过干扰初始的ARF膜相互作用的步骤。
The coatomer is a cytosolic protein complex that reversibly associates with Golgi membranes and is implicated in modulating Golgi membrane transport. The association of beta-COP, a component of coatomer, with Golgi membranes is enhanced by guanosine 5'-[gamma-thio]triphosphate (GTP[gamma-S]), a nonhydrolyzable analogue of GTP, and by a mixture of aluminum and fluoride ions (Al/F). Here we show that the ADP-ribosylation factor (ARF) is required for the binding of beta-COP. Thus, beta-COP contained in a coatomer fraction that has been resolved from ARF does not bind to Golgi membranes, whereas binding can be reconstituted by the addition of recombinant ARF. Furthermore, an N-terminal peptide of ARF, which blocks ARF binding to Golgi membranes, inhibits GTP[gamma-S]- as well as the Al/F-enhanced binding of beta-COP. We show that Golgi coat protein binding involves a sequential reaction where an initial interaction of ARF and GTP[gamma-S] with the membrane allows subsequent binding of beta-COP to take place in the absence of free ARF and GTP[gamma-S]. The fungal metabolite brefeldin A, which is known to prevent the association of coat proteins with Golgi membrane, is shown to exert this effect by interfering with the initial ARF-membrane interaction step.