Zhao L, Helms J B, Brunner J, Wieland F T
Biochemie-Zentrum Heidelberg, University of Heidelberg, Im Neuenheimer Feld 328, 69120 Heidelberg, Germany.
J Biol Chem. 1999 May 14;274(20):14198-203. doi: 10.1074/jbc.274.20.14198.
A site-directed photocross-linking approach was employed to determine components that act downstream of ADP-ribosylation factor (ARF). To this end, a photolabile phenylalanine analog was incorporated at various positions of the putative effector region of the ARF molecule. Depending on the position of incorporation, we find specific and GTP-dependent interactions of ARF with two subunits of the coatomer complex, beta-COP and gamma-COP, as well as an interaction with a cytosolic protein (approximately 185 kDa). In addition, we observe homodimer formation of ARF molecules at the Golgi membrane. These data suggest that the binding site of ARF to coatomer is at the interface of its beta- and gamma-subunits, and this is in close proximity to the second site of interaction of coatomer with the Golgi membrane, the binding site within gamma-COP for cytosolic dibasic/diphenylalanine motifs.
采用定点光交联方法来确定在ADP-核糖基化因子（ARF）下游起作用的组分。为此，将一种对光不稳定的苯丙氨酸类似物掺入ARF分子假定效应区的不同位置。根据掺入位置的不同，我们发现ARF与外被体复合物的两个亚基β-COP和γ-COP存在特异性的、依赖于GTP的相互作用，以及与一种胞质蛋白（约185 kDa）存在相互作用。此外，我们观察到ARF分子在高尔基体膜上形成同源二聚体。这些数据表明，ARF与外被体的结合位点位于其β亚基和γ亚基的界面处，且该位点紧邻外被体与高尔基体膜的第二个相互作用位点，即γ-COP内胞质双碱性/双苯丙氨酸基序的结合位点。
