NAD+-dependent ADP-ribosyltransferase in renal brush-border membranes.
NAD+-dependent ADP-ribosyltransferase in renal brush-border membranes.
复制标题
肾刷状缘膜中的 NAD 依赖性 ADP-核糖基转移酶。
DOI：
10.1152/ajpcell.1983.245.5.c449
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发表时间：
1983
期刊：
影响因子：
--
通讯作者：
Curthoys,NP
中科院分区：
文献类型：
--
作者：
Kempson,SA;Curthoys,NP
细胞质中氧化的烟酰胺腺嘌呤二核苷酸（NAD+）可能与肾刷状边界膜（BBM）相互作用并抑制BBM磷酸运输。本研究探讨了可能的相互作用机制。用[腺嘌呤-3H]NAD+孵育BBM，导致3H与BBM酸稳定结合，而用[羰基-14C]NAD+孵育BBM时，14C没有结合。这些数据与adp核糖基化机制一致，涉及adp核糖从NAD+转移到BBM。用[腺苷酸-32P]NAD+和用蛇毒磷酸二酯酶处理BBM时，结合的32P以5'-[32P]AMP的形式释放，证实了这一点。在BBM梯度离心后，adp -核糖基转移酶以与已知BBM酶相同的密度被回收，这表明adp -核糖基转移酶是BBM固有的成分，而不是污染物。这些发现表明细胞质内NAD+可能用于BBM蛋白的adp核糖基化，这可能是调节BBM磷酸盐运输系统的机制。
Oxidized nicotinamide adenine dinucleotide (NAD+) in cytosol may interact with renal brush-border membranes (BBM) and inhibit BBM phosphate transport. The possible mechanism of interaction was investigated in the present study. Incubation of BBM with [adenine-3H]NAD+ led to acid-stable binding of 3H to the BBM, in contrast there was no binding of 14C when [carbonyl-14C]NAD+ was used. The data are consistent with an ADP-ribosylation mechanism involving transfer of ADP-ribose from NAD+ to BBM. This was confirmed by using [adenylate-32P]NAD+ and by the release of bound 32P in the form of 5'-[32P]AMP when the BBM were treated with snake venom phosphodiesterase. After gradient centrifugation of BBM the ADP-ribosyltransferase was recovered at the same density as known BBM enzymes, indicating that ADP-ribosyltransferase is an intrinsic BBM component and not a contaminant. These findings indicate that cytosolic NAD+ may be used for ADP-ribosylation of BBM proteins and that this may be a mechanism for regulating the BBM phosphate transport system.