Transphosphorylation and G protein activation.
Transphosphorylation and G protein activation.
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DOI：
10.1016/0006-2952(90)90420-p
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发表时间：
1990-05
影响因子：
5.8
通讯作者：
Angela S. Otero
中科院分区：
文献类型：
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作者：
Angela S. Otero
多种基本细胞功能的控制涉及一组蛋白质，其特征在于特异性结合鸟嘌呤核苷酸和水解GTP的能力[11]。这个GTP结合蛋白家族包括微管蛋白，微管的基本单位[2]，蛋白质合成的起始和延伸因子[3]，以及介导跨膜信号传导的G蛋白（4-61. GTP结合蛋白在活性（GTP结合）和非活性（GDP结合）形式之间循环，其在与特定系统的其他蛋白质组分的相互作用方面显着不同。这些fnrmr; c~ rmmnl; chJ h之间的转换。7mmn ~ 1;~ 1CnP-CTP I-1111.2. J. Tcyururrul UYI μ II交换和GTP水解，并导致特异性细胞过程的瞬时激活[1 -6]。鸟嘌呤核苷酸结合蛋白对GTP的绝对需求以及GDP和GTP对GTP结合蛋白活性的相反影响意味着由GTP水解产生的GDP的再磷酸化对其功能是必不可少的。线粒体外GTP再生可使线粒体外GTP再生的能力增强。r\-，.--我：“我-。l rL. _^.. _ 1.* _^ _ L，.“L^ _. 1，.*：，.由鸟苷三磷酸单磷酸激酶（2GDP= GMP+ GTP）、鸟苷酸激酶（GDP+ ADP= GTP+ AMP）和核苷二磷酸激酶（GDP+ NTP= GTP+ NDP）催化的反应[7]。后一种酶是普遍存在的，并且在大多数组织中，其活性比核苷酸单磷酸激酶的活性大10至100倍[8]。核苷二磷酸激酶（NDPK）存在于富含GT结合蛋白的制剂中，例如微管蛋白[9-111]、视杆外节[12，131]、核糖体[14，15]和质膜（见下文）。已经提出，这种关联不是偶然的，而是反映了GTP结合蛋白和NDPK之间的生理相关联系[11，15-201]，从而提高了GTP不仅可以作为生理激活剂，而且可以作为GTP结合蛋白的调节剂的可能性。这篇综述的目的是研究实验证据，导致这一命题的具体情况下，膜结合G蛋白，控制
The control of a variety of essential cellular functions involves a group of proteins characterized by specific binding of guanine nucleotides and the ability to hydrolyze GTP [11. This family of GTP-binding proteins includes tubulin, the basic unit of microtubules [2], the initiation and elongation factors of protein synthesis[3], and the G proteins that mediate transmembrane signalling (4-61. GTP-binding proteins cycle between active (GTP bound) and inactive (GDP bound) forms, that differ markedly in terms of their interactions with other protein components of a particular system. Conversion between these fnrmr; c~ rmmnl; chJ h. 7 rmn~~ ont;~ l CnP-CTP I” 1111.2.. l U~~““X~“““~ U “J. Tcyururrul UYI mu II exchange and GTP hydrolysis, and leads to transient activation of specific cellular processes[l-6]. The absolute requirement of guanine nucleotide binding proteins for GTP and the opposing effects of GDP and GTP on the activity of GTP-binding proteins imply that rephosphorylation of GDP arising from GTP hydrolysis is indispensable for their function. Extramitochondrial GTP regeneration can L,.,. r\-,.--l:“L-. l rL. _^.. _ 1.* _^^^ _ L,.“_L^ _.. 1,.*:,... _^^^“e dcL” L ‘Ip, IsIIeu r ‘lluugll~, d,,~~, ll” a~, l,“‘~, allUll, c; dL_ tions catalyzed by guanosine triphosphate monophosphate kinase(2GDP= GMP+ GTP), guanylate kinase(GDP+ ADP= GTP+ AMP) and by nucleoside diphosphate kinase (GDP+ NTP= GTP+ NDP) t[7]. The latter enzyme is ubiquitous, and in most tissues its activity is lo-to lOO-fold greater than the activity of the nucleotide monophosphate kinases [8]. Nucleoside diphosphate kinase (NDPK) is found in preparations enriched in GTP-binding proteins, such as microtubule proteins [9-111, rod outer segments [12, 131, ribosomes[14, 15] and plasma membranes(see below). It has been proposed that this association is not fortuitous, but reflects a physiologically relevant connection between GTP-binding proteins and NDPK [11, 15-201, raising the possibility that GTP may act not only as the physiological activator, but also as a regulator of GTP-binding proteins. The purpose of this review is to examine the experimental evidence that led to this proposition in the specific case of the membrane-bound G proteins that control