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Modification of the apoptotic-like effects of MBP protein overexpression in E. coli by fusion with 14-3-3 derived
E Markiewicz1, G Wilczynski, J Filipski
1Laboratorium Biochemii Genetycznej, Uniwersytet Wroclawski, Wroclaw, Poland.
Abstract:
Overexpression of even non-toxic proteins in bacteria causes a starvation-like response: the arrest of bacterial proliferation and apoptotic-like suicidal cell death. We have shown here that, as in the cells of higher organisms, these effects are accompanied by DNA degradation. The fusion with the bacterial MBP of a polypeptide, belonging to the 14-3-3 family and normally expressed in pumpkin (C. pepo), modifies the apoptotic-like effects of overexpression of this protein in E. coli. Fusion of the full length 14-3-3 protein with the MBP considerably slows down the DNA degradation caused by overexpression of the unmodified MBP. Overexpression of the construct containing a truncated version of the 14-3-3 polypeptide causes immediate arrest of bacterial growth and rapid degradation of the chromosomal DNA. This result suggests that the DNA degradation in bacteria is an active process which can be modified to some extent by an endogenous protein.
Insights
Bacterial overexpression of proteins triggers a starvation response, including DNA degradation. A pumpkin protein (14-3-3) fused to MBP modifies this process, suggesting DNA degradation is an active, modifiable mechanism.
Area of Science:
- Molecular Biology
- Bacterial Physiology
Background:
- Overexpression of proteins in bacteria can induce a starvation-like response, characterized by growth arrest and apoptotic-like cell death.
- This response in bacteria is accompanied by DNA degradation, similar to processes observed in higher organisms.
Purpose of the Study:
- To investigate the role of a plant-derived 14-3-3 protein in modulating bacterial apoptotic-like effects and DNA degradation.
- To determine if bacterial DNA degradation is an active process influenced by endogenous proteins.
Main Methods:
- Bacterial expression of fusion proteins: maltose-binding protein (MBP) fused to full-length or truncated 14-3-3 polypeptide from pumpkin (C. pepo).
- Monitoring of bacterial proliferation (growth arrest).
- Assessment of chromosomal DNA degradation.
Main Results:
- Fusion of full-length 14-3-3 with MBP significantly slowed DNA degradation induced by MBP overexpression.
- Overexpression of a construct with truncated 14-3-3 led to immediate growth arrest and rapid DNA degradation.
- These findings indicate that DNA degradation in bacteria is an active, regulated process.
Conclusions:
- The plant-derived 14-3-3 protein can modify the apoptotic-like response and DNA degradation in bacteria.
- Bacterial DNA degradation is an active process that can be modulated by specific protein interactions.
