Inhibition of apoptosis by Z-VAD-fmk in SMN-depleted S2 cells

UMMS Affiliation

Department of Medicine and Program in Neuroscience

Publication Date


Document Type



Amino Acid Chloromethyl Ketones; Animals; Antibodies; Apoptosis; Caspases; Cell Line; Cyclic AMP Response Element-Binding Protein; Cysteine Proteinase Inhibitors; Drosophila; Nerve Tissue Proteins; RNA Interference; RNA, Double-Stranded; RNA-Binding Proteins; Signal Transduction


Life Sciences | Medicine and Health Sciences


Spinal muscular atrophy is an autosomal recessive motor neuron degenerative disorder, caused by the loss of telomeric copy of the survival motor neuron gene (SMN1). To better understand how motor neurons are targeted in Spinal muscular atrophy patients, it is important to study the role of SMN protein in cell death. In this report, we employed RNA interference (RNAi) to study the loss-of-function of SMN in Drosophila S2 cells. A 601-base pair double-stranded RNA (dsRNA) of Drosophila SMN (dSMN) was used for silencing the dSMN. Our data indicate that dSMN RNAi resulted in more than 90% reduction of both RNA and protein. Further analysis of S2 cells by cell death ELISA and flow cytometry assays revealed that reduction of dSMN expression significantly increased apoptosis. The cell death mediated by SMN depletion is caspase-dependent and specifically due to the activation of the endogenous caspases, DRONC and DRICE. Significantly, the effect of dSMN RNAi was reversed by a peptide caspase inhibitor, Z-VAD-fmk. These results suggest that dSMN is involved in signal pathways of apoptotic cell death in Drosophila. Hence, the model system of reduced SMN expression by RNAi in Drosophila could be exploited for identification of therapeutic targets.

DOI of Published Version



J Biol Chem. 2003 Aug 15;278(33):30993-9. Epub 2003 Jun 3. Link to article on publisher's site

Journal/Book/Conference Title

The Journal of biological chemistry

Related Resources

Link to Article in PubMed

PubMed ID