IN-VITRO RECONSTITUTION OF PHAGOSOME-ENDOSOME FUSION - EVIDENCE FOR REGULATION BY HETEROTRIMERIC GTPASES
IN-VITRO RECONSTITUTION OF PHAGOSOME-ENDOSOME FUSION - EVIDENCE FOR REGULATION BY HETEROTRIMERIC GTPASES
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DOI：
10.1006/abbi.1995.1172
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发表时间：
1995-03-10
影响因子：
3.9
通讯作者：
STAHL, PD
中科院分区：
文献类型：
--
作者：
BERON, W;COLOMBO, MI;STAHL, PD
我们已经评估了异源三聚体GTP酶在吞噬体和内体的体外融合中的作用。发现高度纯化的吞噬体含有异源三聚体GTP结合蛋白的G α s、G α i1、G α i2、G α i3和G β亚基。使用体外吞噬体-内体融合测定建立了G蛋白的功能作用。首先，向体外测定中加入AlF 4-和纯化的G β γ亚基阻断了融合，表明异源三聚体G蛋白可能在吞噬体成熟中直接或间接发挥作用。其次，当囊泡与优先激活G α的肽一起孵育时，观察到显著的抑制作用。用霍乱毒素（一种已知激活G α s的试剂）观察到对吞噬体-内体融合的类似作用。我们的研究结果表明，一个或多个异源三聚体G蛋白，包括Gs，介导和/或调节吞噬体-内体融合。(C)出版社：Academic Press
We have assessed the role of heterotrimeric GTPases on in vitro fusion of phagosomes and endosomes. Highly purified phagosomes were found to contain G alpha s, G alpha i1, G alpha i2, G alpha i3, and G beta subunits of heterotrimeric GTP-binding proteins. A functional role for G proteins was established using an in vitro phagosome-endosome fusion assay, First, addition of AlF4- and purified G beta gamma subunits to the in vitro assay blocked fusion, indicating that heterotrimeric G proteins may play a role, either direct or indirect, in phagosome maturation. Second, a striking inhibitory effect was observed when the vesicles were incubated with peptides that preferentially activate G alpha s. A similar effect on phagosome-endosome fusion was observed with cholera toxin, a reagent known to activate G alpha s. Our results suggest that one or more heterotrimeric G proteins, including Gs, mediate and/or regulate phagosome-endosome fusion. (C) 1995 Academic Press, Inc.