Formation of 50 kbp chromatin fragments in isolated liver nuclei is mediated by protease and endonuclease activation

FEBS Letters

Zhivotovsky, Boris¹  Nicotera, Pierluigi¹  Gahm, Annie¹  Orrenius, Sten¹  Wade, David¹ 

[1] Institute of Environmental Medicine, Division of Toxicology, Karolinska Institutet, Box 210, S-17177 Stockholm, Sweden

关键词: Apoptosis;    Chromatin;    Endonuclease;    Protease;    Liver nuclei;    ATA;    aurintricarboxylic acid;    DTT;    dithiothreitol;    EDTA;    ethylenediamine tetraacetic acid;    EGTA;    ethylene glycol-O;    O′-bis(2-aminoethyl-N;    N;    N′ N′-tetraacetic acid;    HMW DNA;    high molecular weight DNA;    NMDA;    N-methyl-d-aspartate;    MK-801;    (+)-methyl-10-;    11-dihydro-5H-benzo(a;    d)cyclohepten-5;    10-imine hydrogen maleate;    PMSF;    phenylmethanesulfonyl flouride;    TLCK;    N α-p-tosyl-l-lysine chloromethyl ketone;    TPCK;    N-tosyl-l-phenylalanine chloromethyl ketone;   

DOI  :  10.1016/0014-5793(94)00827-2

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Isolated rat liver nuclei were incubated in the presence of divalent cations, and the mechanisms underlying the subsequent chromatin fragmentation were investigated. Either of the two cations, Ca²⁺ or Mg²⁺ was sufficient to produce chromatin fragments with sizes between 700 and 300 kbp. The formation of chromatin fragments of 50 kbp as well as the following internucleosomal DNA cleavage - which are characteristic of apoptosis - were markedly stimulated in the presence of Ca²⁺. Chromatin degradation to 50 kbp and smaller (oligonucleosome-size) fragments was prevented by inhibitors of endonucleases and serine proteases. We suggest a mechanism whereby the concerted activity of both proteases and endonucleases results in the widespread chromatin cleavage observed in cellls undergoing apoptosis.

【 授权许可】

Unknown