REGULATION OF ADP RIBOSYLATION FACTOR

这项工作的主要目的是阐明生物化学 调节GTP结合蛋白ARF的机制，并在此过程中， 进一步了解ARF在膜运输中的作用。 ARF与靶蛋白的相互作用依赖于磷脂。 Arf上的磷脂酰肌醇4，5-二磷酸（PIP 2）结合位点具有 已被初步鉴定为包含的残基178和181的 羧基末端结构域。 PIP 2与该位点的结合促进 与Arf GAP的相互作用。 这与以下假设是一致的： 特定的脂质可以指导Arf与特定蛋白质的相互作用， 从而提供了一种对膜中Arf依赖性事件进行排序的方法， 交通 发现PIP 2和PA是ARF - ARF GAP所必需的 我们已经能够取得一些进展， 纯化后一种蛋白质。 蛋白质现已被纯化 大约2,000倍，并已显示出与大衣不同 蛋白质和其他已知的Arf GAP。 两个Arf GAP具有相似的 底物的偏好，但不同的是，他们的监管， 磷脂 多个GAP可以独立地调节Arf， 多个作用部位。

The main objective of this work is to elucidate the biochemical mechanisms regulating the GTP-binding protein ARF and, in so doing, to further our understanding of the role of ARF in membrane traffic. ARF's interaction with target proteins is dependent on phospholipids. A phosphatidylinositol 4,5-bisphosphate (PIP2) binding site on Arf has been tentatively identified as comprising residues 178 and 181 of the carboxy terminal domain. Binding of PIP2 to this site promotes interaction with Arf GAP. This is consistent with the hypothesis that specific lipids may direct Arf interactions with specific proteins and thereby provide a means of ordering Arf-dependent events in membrane traffic. Having found that PIP2 and PA were required for ARF - ARF GAP interaction, we have been able to make some progress in the purification of the latter protein. The protein has now been purified approximately 2,000 fold and has been shown to be distinct from coat proteins and the other known Arf GAP. The two Arf GAPs had similar substrate preferences but differed in their regulation by phospholipids. Multiple GAPs may independently regulate Arf at Arf's multiple sites of action.