一氧化氮调节视杆外段蛋白的内源性ADP核糖基化。

Nitric oxide-regulated endogenous ADP-ribosylation of rod outer segment proteins.

作者信息

Pozdnyakov N, Lloyd A, Reddy V N, Sitaramayya A

机构信息

Eye Research Institute, Oakland University, Rochester, MI 48309.

出版信息

Biochem Biophys Res Commun. 1993 Apr 30;192(2):610-5. doi: 10.1006/bbrc.1993.1459.

DOI:10.1006/bbrc.1993.1459

PMID:8484771

Abstract

Both membrane and cytosolic fractions of retinal rod outer segments contain ADP-ribosylases that modify proteins in the respective fractions. Nitroprusside and endogenously produced NO regulate the activities of these ADP-ribosylases. The ADP-ribosylation of the membrane proteins of molecular weight 116K, 66K and 46K is inhibited by NO and nitroprusside, while that of the 38K cytosolic protein and the 39K membrane-associated protein is activated. The 39K protein is identified as the alpha-subunit of G-protein. The ADP-ribosylation of this protein is activated 6 to 11-fold by NO suggesting that NO may play a significant role in modulating the activity of G-protein in visual transduction.

摘要

视网膜视杆细胞外段的膜组分和胞质组分均含有ADP核糖基化酶，这些酶可修饰各自组分中的蛋白质。硝普钠和内源性产生的一氧化氮（NO）调节这些ADP核糖基化酶的活性。分子量为116K、66K和46K的膜蛋白的ADP核糖基化被NO和硝普钠抑制，而38K胞质蛋白和39K膜相关蛋白的ADP核糖基化则被激活。39K蛋白被鉴定为G蛋白的α亚基。该蛋白的ADP核糖基化被NO激活6至11倍，这表明NO可能在视觉转导中调节G蛋白活性方面发挥重要作用。