Post-translational processing of rac p21s is important both for their interaction with the GDP/GTP exchange proteins and for their activation of NADPH oxidase.
Post-translational processing of rac p21s is important both for their interaction with the GDP/GTP exchange proteins and for their activation of NADPH oxidase.
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DOI：
10.1016/s0021-9258(18)35665-5
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发表时间：
1992-12
期刊：
影响因子：
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通讯作者：
Satoshi Ando;K. Kaibuchi;Takuya Sasaki;Kunihiko Hiraoka;Takayuki Nishiyama;T. Mizuno;Makoto AsadaS;Hiroyuki NunoiQ;Ichiro MatsudaQ;Yoshiharu Matsuurall;Paul PolakisII;F. McCormick;Y. Takai
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文献类型：
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作者：
Satoshi Ando;K. Kaibuchi;Takuya Sasaki;Kunihiko Hiraoka;Takayuki Nishiyama;T. Mizuno;Makoto AsadaS;Hiroyuki NunoiQ;Ichiro MatsudaQ;Yoshiharu Matsuurall;Paul PolakisII;F. McCormick;Y. Takai
rac1 和 rac2 p21s 是 ras p21 样的小 GTP 结合蛋白，参与吞噬细胞中 NADPH 氧化酶催化的超氧化物生成。 rac1 和 rac2 p21 在其 C 末端区域具有 Cys-A-A-Leu（A = 脂肪族氨基酸）结构，该结构可能会经历翻译后加工，包括异戊二烯化、蛋白水解和羧基甲基化。我们研究了 rac p21s 的这种翻译后加工在与 rac p21s 的刺激性和抑制性 GDP/GTP 交换蛋白（称为 smg GDS 和 rho GDI）相互作用中的功能，以及在它们的 NADPH 氧化酶激活中的功能。我们在昆虫细胞中生产了人类重组 rac1 和 rac2 p21，并分别以翻译后加工和未加工的形式从膜和可溶性部分中纯化出它们。翻译后处理的 rac1 和 rac2 p21 对 smg GDS 和 rho GDI 敏感，但翻译后未处理的 rac1 和 rac2 p21 对它们不敏感。翻译后加工的 rac1 和 rac2 p21 的 GTP gamma S（鸟苷 5'-(3-O-硫代）三磷酸）结合形式刺激 NADPH 氧化酶活性，但翻译后未加工的 rac1 和 rac2 p21 的效果要差得多。这些结果表明，rac1 和 rac2 p21 均刺激 NADPH 氧化酶活性，并且它们的翻译后加工不仅对于它们与 smg GDS 和 rho GDI 的相互作用很重要，而且对于它们的 NADPH 氧化酶激活也很重要。
rac1 and rac2 p21s are ras p21-like small GTP-binding proteins which are implicated in the NADPH oxidase-catalyzed superoxide generation in phagocytes. rac1 and rac2 p21s have a Cys-A-A-Leu (A = aliphatic amino acid) structure in their C-terminal region which may undergo post-translational processing including prenylation, proteolysis, and carboxyl methylation. We studied the function of this post-translational processing of rac p21s in their interaction with the stimulatory and inhibitory GDP/GTP exchange proteins for rac p21s, named smg GDS and rho GDI, and in their NADPH oxidase activation. We produced human recombinant rac1 and rac2 p21s in insect cells and purified them from the membrane and soluble fractions as the post-translationally processed and unprocessed forms, respectively. Post-translationally processed rac1 and rac2 p21s were sensitive to both smg GDS and rho GDI, but post-translationally unprocessed rac1 and rac2 p21s were insensitive to them. The GTP gamma S (guanosine 5'-(3-O-thio)triphosphate)-bound form of post-translationally processed rac1 and rac2 p21s stimulated the NADPH oxidase activity, but post-translationally unprocessed rac1 and rac2 p21s were far less effective. These results indicate that both rac1 and rac2 p21s stimulate the NADPH oxidase activity and that their post-translational processing is important not only for their interaction with smg GDS and rho GDI but also for their NADPH oxidase activation.