1. How did you compose this image?
This image depicts a self-replicator in the bacterial cell. In the image, the white outline represents the membrane of a bacterial cell with a flagellum and cilia. Inside the cell, molecular chaperones (the yellow cylinders) assist newly synthesized polypeptides (the green and yellow curves) to mature correctly into chaperone proteins and other proteins (other green shapes). Newly matured chaperones are allocated to the protein folding process, whereas other proteins are allocated to other processes. The stress (the red explosion) that limits the protein maturation process (the red arrow), changes the allocation of the proteome by affecting the dynamics of the self-replicator. The image also brings to mind another well-known self-replicator in which ribosomes synthesize ribosomal proteins as well as other proteins. The stress on the translation causes more ribosomes to synthesize themselves.
2. How does this image reflect your scientific research?
It is an important issue to elucidate how bacterial cells redistribute protein resources to adapt to the stress. In our research, we developed a self-replication model to study the steady-state change in proteome allocation under stress conditions. The dynamics of protein resource conversions were described by several coarse-grained fluxes of protein resources. The allocation fractions of proteome affect the fluxes, and the optimal allocation strategy was obtained by using the method of flux balance analysis and maximizing growth rate. The self-replicator depicted by the image represents the major novelty of our model: characterizing the role of chaperones (the yellow cylinders) in optimizing the flux of correct protein maturation, corresponding to the growth rate (the red arrow) under the stress (the red explosion) limiting protein maturation. As predicted by the self-replication model, the proteome fraction for chaperones should be increased to reduce the limitation on the correct maturation flux, which is in line with the experiments.
3. Can you please provide a few real-world examples of your research?
Many naturally occurring stresses may affect protein maturation, such as thermal, oxidative, and acidic stresses. Experimental evidence indicates that chaperone genes are more or less up-regulated under thermal, oxidative, and acidic stresses. Our self-replication model can be used to understand the change in gene expression under these kinds of stresses; for example, we studied the case with a constitutive gene in E.coli grown with acetic acid or paraquat.
4. How does your research apply to those who are not working in your specific field?
Self-replication phenomenon is common in biology. If the allocation of some kind of cellular resources affects the dynamics of a self-replicator, then a model similar to ours could be developed to study it.
5. Do you have a website where our readers can view your recent research?
The readers may view my recent research on ResearcherID: http://www.researcherid.com/rid/E-2316-2018
- Qing Zhang, Rui Li, Junbai Li, Hualin Shi