Endogenous ADP-ribosylation for eukaryotic elongation factor 2: evidence of two different sites and reactions
Endogenous ADP-ribosylation for eukaryotic elongation factor 2: evidence of two different sites and reactions
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DOI：
10.1002/cbf.1265
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发表时间：
2006-07-01
影响因子：
3.6
通讯作者：
Bermek, Engin
中科院分区：
文献类型：
--
作者：
Bektas, Muhammet;Nurten, Rustem;Bermek, Engin
真核细胞延伸因子2可以在没有白喉毒素的情况下在内源性转移酶的作用下进行ADP-核糖基化。旨在深入了解内源性ADP-核糖基化的性质的研究表明，在某些情况下，该反应可能是由于游离ADP-核糖与延伸因子2的共价结合。结合游离ADP-核糖，NAD-和内源性转移酶依赖的ADP-核糖基化被认为是不同的反应不同的结果。游离的ADP-ribosc可以结合到先前通过白喉毒素或内源性转移酶进行ADP-核糖基化的延伸因子2。游离ADP-核糖的结合被中性NH_2OH、L-赖氨酸和苦基磺酸盐抑制，而内源性ADP-核糖基转移酶被NAD糖水解酶抑制剂和L-精氨酸抑制。ADP-核糖基-延伸因子2加合物在结合游离ADP-核糖后形成，对中性NH 2 OH具有抗性，但在用NaOH处理后几乎完全分解。内源性转移酶依赖的腺苷三磷酸化产物对NH_2OH和NaOH处理有部分抗性。此外，在白喉毒素和烟酰胺存在下，该反应被逆转。这两种类型的内源性ADP-核糖基化引起的抑制聚苯丙氨酸的合成。因此，这项研究提供了证据，真核延伸因子2的两种不同类型的内源性ADP核糖基化的存在。参与这些反应的各个位点彼此不同，也不同于白喉毒素攻击的白喉酰胺。版权所有（c）2005年约翰威利父子有限公司。
Eukaryotic elongation factor 2 can undergo ADP-ribosylation in the absence of diphtheria toxin under the action of an endogenous transferase. The investigation which aimed to gain insight into the nature of endogenous ADP-ribosylation revealed that this reaction may be, in some cases, due to covalent binding of free ADP-ribose to elongation factor 2. Binding of free ADP-ribose, and NAD- and endogenous transferase-dependent ADP-ribosylation were suggested to be distinct reactions by different findings. Free ADP-ribosc could bind to elongation factor 2 previously subjected to ADP-ribosylation by diphtheria toxin or endogenous transferase. The binding of free ADP-ribose was inhibited by neutral NH2OH, L-lysine and picrylsulfonate, whereas endogenous ADP-ribosyltransferase was inhibited by NAD glycohydrolase inhibitors and L-arginine. The ADP-ribosyl-elongation factor 2 adduct which formed upon binding of free ADP-ribose was resistant to neutral NH2OH, but decomposed almost completely upon treatment with NaOH. The product of endogenous transferase-dependent ADPribosylation was partially resistant to NH2OH and NaOH treatment. Moreover, this reaction was reversed in the presence of diphtheria toxin and nicotinamide. Both types of endogenous ADP-ribosylation gave rise to inhibition of polyphenylalanine synthesis. This study thus provides evidence for the presence of two different types of endogenous ADP-ribosylation of eukaryotic elongation factor 2. The respective sites involved in these reactions are distinct from one another as well as from diphthamide, the site of attack by diphtheria toxin. Copyright (c) 2005 John Wiley & Sons, Ltd.