C‐terminal 15 kDa fragment of cytoskeletal actin is posttranslationally N‐myristoylated upon caspase‐mediated cleavage and targeted to mitochondria

FEBS Letters

Nakano, Kengo¹  Sakurai, Nagisa¹  Utsumi, Toshihiko¹  Ishisaka, Rumi¹ 

[1] Department of Biological Chemistry, Faculty of Agriculture, Yamaguchi University, Yamaguchi 753-8515, Japan

关键词: Posttranslational modification;    Posttranslational N-myristoylation;    Caspase substrate;    Protein N-myristoylation;    Protein acylation;    Actin;    tBID;    truncated BID;    tActin;    truncated actin;    TNF;    tumor necrosis factor;    NMT;    N-myristoyltransferase;    PCR;    polymerase chain reaction;    DPBS;    Dulbecco's phosphate-buffered saline;    SDS;    sodium dodecyl sulfate;    PAGE;    polyacrylamide gel electrophoresis;   

DOI  :  10.1016/S0014-5793(03)00180-7

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

To detect the posttranslational N-myristoylation of caspase substrates, the susceptibility of the newly exposed N-terminus of known caspase substrates to protein N-myristoylation was evaluated by in vivo metabolic labeling with [³H]myristic acid in transfected cells using a fusion protein in which the query sequence was fused to a model protein. As a result, it was found that the N-terminal nine residues of the newly exposed N-terminus of the caspase-cleavage product of cytoskeletal actin efficiently direct the protein N-myristoylation. Metabolic labeling of COS-1 cells transiently transfected with cDNA coding for full-length truncated actin (tActin) revealed the efficient incorporation of [³H]myristic acid into this molecule. When COS-1 cells transiently transfected with cDNA coding for full-length actin were treated with staurosporine, an apoptosis-inducing agent, an N-myristoylated tActin was generated. Immunofluorescence staining coupled with MitoTracker or fluorescence tagged-phalloidin staining revealed that exogenously expressed tActin colocalized with mitochondria without affecting cellular and actin morphology. Taken together, these results demonstrate that the C-terminal 15 kDa fragment of cytoskeletal actin is posttranslationally N-myristoylated upon caspase-mediated cleavage during apoptosis and targeted to mitochondria.

【 授权许可】

Unknown