title: Intracellular expression of a functional short peptide confers resistance to apoptosis.
abstract: Expression of free short peptides could potentially be used to modulate biochemical cascades and consequently to change cellular phenotypes. Here we demonstrate that expression of a short peptide of 15 amino acids, including the pseudo-substrate site of the baculovirus-apoptosis inhibitor P35, Asp-Gln-Met-Asp (DQMD), leads to abrogation of the apoptotic cascade. Treatment of cells, expressing the DQMD peptide with two apoptosis inducers, etoposide and sodium nitroprusside, (SNP) results in blocking of the apoptotic cascade, indicated by DNA fragmentation and caspase activation. Consequently, stable expression of the DQMD peptide led to protection of cells, following induction of apoptosis and to the outgrowth and enrichment of resistant cell colonies. The results presented in this work demonstrate for the first time the feasibility of expressing in cells functional short peptides that block apoptotic cascade, and to rescue the phenotypically altered cells in a stable fashion. This approach is general and could be applied to the study of other peptides and the respective biochemical cascades.
mesh_terms: D016475:3T3 Cells; D000818:Animals; D017209:Apoptosis / Q000187:drug effects / Q000235:genetics*; D053148:Caspase 3; D020169:Caspases / Q000187:drug effects; D002999:Clone Cells / Q000187:drug effects / Q000378:metabolism; D053938:DNA Fragmentation / Q000187:drug effects; D004351:Drug Resistance / Q000235:genetics; D005047:Etoposide / Q000494:pharmacology; D005347:Fibroblasts / Q000187:drug effects / Q000378:metabolism; D006801:Humans; D051034:Inhibitor of Apoptosis Proteins; D007668:Kidney / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D051379:Mice; D009599:Nitroprusside / Q000494:pharmacology; D019384:Nucleic Acid Synthesis Inhibitors / Q000494:pharmacology; D010446:Peptide Fragments / Q000235:genetics / Q000378:metabolism*; D010641:Phenotype; D015398:Signal Transduction / Q000187:drug effects / Q000235:genetics*; D014764:Viral Proteins / Q000235:genetics / Q000378:metabolism*
chemical_list: D051034:Inhibitor of Apoptosis Proteins; D019384:Nucleic Acid Synthesis Inhibitors; D010446:Peptide Fragments; D014764:Viral Proteins; C086430:inhibitor of apoptosis, Nucleopolyhedrovirus; D009599:Nitroprusside; D005047:Etoposide; C505407:CASP3 protein, human; C505409:Casp3 protein, mouse; D053148:Caspase 3; D020169:Caspases