Prasad S, Walent J, Dritschilo A
Department of Radiation Medicine, Georgetown University Medical Center, Washington, DC 20007.
Biochem Biophys Res Commun. 1994 Oct 28;204(2):772-9. doi: 10.1006/bbrc.1994.2526.
Poly and mono (ADP-ribosyl)transferases catalyze the transfer of ADP-ribose from nicotinamide adenine dinucleotide (NAD) to acceptor proteins. Protein substrates of ADP-ribosylation reactions were investigated in human cervical carcinoma (HeLa) cells in the exponential phase of growth. Permeabilized cells were incubated with [32P]-NAD and ADP-ribosylated proteins were detected by two-dimensional polyacrylamide gel electrophoresis (2D-PAGE) and autoradiography. Microsequencing of two coomassie blue-stained proteins corresponding to 32P-labeled proteins on autoradiographs revealed sequence identity with heterogeneous ribonucleoproteins (hnRNPs) A1 and A2/B1, consistent with the isoelectric points, molecular sizes, and 2D-PAGE map locations of these proteins. ADP-ribosylation of hnRNPs may thus serve to modulate the activity of these proteins in the nucleus.
多聚和单（ADP-核糖基）转移酶催化将ADP-核糖从烟酰胺腺嘌呤二核苷酸（NAD）转移至受体蛋白。在处于生长指数期的人宫颈癌（HeLa）细胞中研究了ADP-核糖基化反应的蛋白质底物。用[32P]-NAD孵育通透细胞，通过二维聚丙烯酰胺凝胶电泳（2D-PAGE）和放射自显影检测ADP-核糖基化蛋白。对放射自显影片上与32P标记蛋白相对应的两种考马斯亮蓝染色蛋白进行微量测序，结果显示其与不均一核糖核蛋白（hnRNPs）A1和A2/B1具有序列同一性，这与这些蛋白的等电点、分子大小和2D-PAGE图谱位置一致。因此，hnRNPs的ADP-核糖基化可能有助于调节这些蛋白在细胞核中的活性。
