Nuclear sphingomyelin protects RNA from RNase action

FEBS Letters

Magni, Mariapia Viola²  Leray, Claude¹  Micheli, Marta²  Albi, Elisabetta² 

[1] ETS Strasbourg 10, rue Spielmann, 67065 Strasbourg Cedex, France;Istituto di Patologia Generale Università degli Studi di Perugia, Policlinico Monteluce, Perugia, Italy

关键词: Sphingomyelin;    Phosphatidylcholine;    Sphingomyelin synthase;    Phosphatidylcholine-dependent phospholipase C;    Sphingomyelinase;    Double-stranded RNA;    DAG;    diacylglycerol;    DNT;    digested nuclei after Triton X-100 treatment;    EDTA;    ethylendiaminetetra-acetic acid;    NT;    nuclei after Triton X-100 treatment;    PC;    phosphatidylcholine;    PC-PLC;    phosphatidylcholine-dependent phospholipase C;    PE;    phosphatidylethanolamine;    PI;    phosphatidylinositol;    PLs;    phospholipids;    PS;    phosphatidylserine;    SM;    sphingomyelin;    N-SMase;    neutral sphingomyelinase;    SM synthase;    sphingomyelin synthase;    TLC;    thin layer chromatography;    Tris;    hydroxymethylaminomethane;   

DOI  :  10.1016/S0014-5793(98)00810-2

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Chromatin phospholipidic fraction, as previously demonstrated, shows the same localization as RNA inside the nuclei. DNase and RNase treatment of nuclei removed almost totally the DNA, 63% of RNA and caused a 50% loss of phospholipids. The aim of the present investigation is to study the fraction of RNase undigested nuclear RNA and its relationship with the phospholipids still present in the nuclei. Isolated hepatocyte nuclei were treated with Triton X-100 and digested with RNase and DNase. The undigested nuclear material contained proteins (98%) and a small amount of RNA (1.7%), DNA (0.4%) and phospholipids (0.18%). The analysis of phospholipids showed the presence of two components only, namely phosphatidylcholine and sphingomyelin. In the same complex, the activity of sphingomyelin synthase, phosphatidylcholine-dependent phospholipase C and neutral sphingomyelinase has been detected. Treatment of isolated RNA with neutral sphingomyelinase modified the RNA in RNase sensitive RNA, thus suggesting that the SM may represent a bridge between two RNA strands possibly regulating transcription.

【 授权许可】

Unknown