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Updated: Aug 16, 2026
Peptide-based Identification of Functional Motifs and their Binding Partners
Published on: June 30, 2013
Expression of an anti apoptotic recombinant short peptide in mammalian cells
S Matza-Porges1, I Horresh, E Tavor
1Department of Virology, The Hebrew University-Hadassah Medical School, The Hebrew University of Jerusalem, P.O. Box 12272, Jerusalem 91120, Israel.
Abstract:
Understanding the mechanisms of the apoptotic and anti apoptotic processes may lead to a better way to control these cascades. Here we demonstrated for the first time the feasibility to express a short functional peptide in mammalian cells that abrogates the apoptosis cascade through interference with the proteolytic activity of the initiator caspase 9 and the executing caspase 3 enzymes. The expression of a short peptide that includes the pseudo-substrate motif of the apoptosis inhibitor protein P35 (Asp-Gln-Met-Asp) leads to the abrogation of cell death induced through either the mitochondrial or the death receptors pathways. Short open reading frames have been detected in several mammalian mRNAs, primarily upstream of the main long reading frame (uORFs), however, direct evidence for de-novo peptides translation has not been provided. Utilizing biochemical and imaging techniques we demonstrate here that the functional recombinant peptide was localized to the cytpoplasmic fraction of the cell. In conclusion, this work demonstrates that ribosomes recognize short ORFs to translate stable short recombinant peptides in mammalian cells. Expression of these intracellular peptides results in the knock down of apoptotic processes to generate apoptosis resistant stable cells.
Insights
Scientists created a functional peptide in mammalian cells that stops apoptosis (programmed cell death) by blocking key enzymes. This breakthrough offers a new way to generate cells resistant to cell death.
Area of Science:
- Cell Biology
- Molecular Biology
- Biochemistry
Background:
- Apoptosis, or programmed cell death, is a critical biological process.
- Dysregulation of apoptosis is implicated in various diseases, including cancer and neurodegeneration.
- Controlling apoptotic cascades offers therapeutic potential.
Purpose of the Study:
- To demonstrate the feasibility of expressing a functional peptide in mammalian cells that inhibits apoptosis.
- To investigate the peptide's mechanism of action on initiator caspase 9 and executing caspase 3.
- To explore the potential of short open reading frames (uORFs) for de-novo peptide translation.
Main Methods:
- Expression of a short peptide containing the P35 pseudo-substrate motif (Asp-Gln-Met-Asp) in mammalian cells.
- Utilizing biochemical assays to confirm peptide functionality.
- Employing imaging techniques to determine subcellular localization of the expressed peptide.
- Assessing the impact of peptide expression on apoptosis induced by mitochondrial and death receptor pathways.
Main Results:
- Successfully expressed a functional peptide in mammalian cells that abrogates the apoptosis cascade.
- The peptide interferes with the proteolytic activity of caspase 9 and caspase 3.
- Cell death induced via both mitochondrial and death receptor pathways was inhibited.
- Biochemical and imaging data confirmed the peptide's localization to the cytoplasmic fraction.
- Demonstrated that mammalian ribosomes can translate stable short peptides from uORFs.
Conclusions:
- Mammalian cells can translate stable functional peptides from short open reading frames.
- The expressed peptide effectively inhibits apoptosis by targeting key caspases.
- This approach generates apoptosis-resistant cells, offering potential applications in cell-based therapies and research.
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