Correlation between structure of Bcl-2 and its inhibitory function of JNK and caspase activity in dopaminergic neuronal apoptosis

Won Seok Choi, So Young Yoon, In Ick Chang, Eui Ju Choi, Hyewhon Rhim, Byung K. Jin, Tae H. Oh, Stanislaw Krajewski, John C. Reed, Young J. Oh

Research output: Contribution to journalArticle

24 Citations (Scopus)

Abstract

To examine the correlation between the structure of Bcl-2 and its inhibitory function of c-Jun N-terminal kinase (JNK) and caspase activity, we established a dopaminergic neuronal cell line, MN9D overexpressing Bcl-2 (MN9D/Bcl-2) or its structural mutants. The mutants comprised a point mutation in the BH1 (G145A; MN9D/BH1) or BH2 (W188A; MN9D/BH2) domain and a deletion mutation in the C-terminal (MN9D/C22), BH3 (MN9D/BH3), or BH4 (MN9D/BH4) domain. As determined by the TUNEL (terminal deoxynucleotidyltransferase nick end-labeling) and MTT [3-(4,5- dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] reduction assay, apoptotic death of MN9D/Neo cells reached 8090% within 24 h in response to 1 μM staurosporine. Upon staurosporine treatment, JNK activity increased six- to sevenfold over the basal level within 2-4 h. Treatment of MN9D/Neo with both staurosporine and a caspase inhibitor, Z-VAD, attenuated cell death without suppressing JNK activation. Both staurosporine-induced cell death and JNK activation were attenuated in MN9D/Bcl-2. As determined by cleavage of poly(ADP-ribose) polymerase into 85 kDa, Bcl-2 blocked caspase activity as well. When cells overexpressing one of the Bcl-2 mutants were treated with staurosporine, death was attenuated in MN9D/BH1, MN9D/BH2, and MN9D/C22 but not in MN9D/BH3 and MN9D/BH4. Similarly, both JNK and caspase activation were blocked in MN9D/BH1, MN9D/BH2, and MN9D/C22, whereas they were not suppressed in MN9D/BH3 and MN9D/BH4. Taken together, our data indicate that there exists a close structural and functional correlation of Bcl-2 to JNK and caspase activity in staurosporine-induced dopaminergic neuronal cell death.

Original languageEnglish
Pages (from-to)1621-1626
Number of pages6
JournalJournal of Neurochemistry
Volume74
Issue number4
DOIs
Publication statusPublished - 2000 Apr 3

    Fingerprint

Keywords

  • Apoptosis
  • Bcl-2 homology domain
  • MN9D
  • Parkinson's disease

ASJC Scopus subject areas

  • Biochemistry
  • Cellular and Molecular Neuroscience

Cite this