Team:IIT Delhi/Resources
Resource Sharing
The transcription and translation mechanism although theoretically processes, in practice it may not be as predicted. The model considered above (or in general
practice) considers abundance of cellular resources such as ribosomes, or amino acids to
carry out the function . In reality, the present quantity may not be sufficient to the facilitate smooth function of each individual biological processes. When we insert a synthetic
plasmid inside a cell, the host has to share the resources it suppose to use for cell growth
and other activities. One can model the competition of cellular processes as virtual induced negative feedback. Suppose, A and B are two mRNA require the ribosome and the
only available ribosome binds with A due to strong RBS in the sequence, then B wont be
translated to the protein form soon. These kind of behavior is known as post transcriptional control. There could be any possible combination of such competition behavior, as
a case study we are considering a competing between p1 and p4. Such competition introduced two implicit feedback to each other in the oscillator. The model of such dynamics
can be written as,
where the parameters are same as earlier. The model is simulated and response is as
shown in figure below. Here, we observe an increase in period as expected. This is due to an
additional delay involved for ribosome (or any other resource queuing). The competition
of resource sharing may quench the oscillation if the delay is more than required. This
is a preliminary step to understand how the resource may effect the ideal biomolecular
system performance.
Fig. GFP expression with and without resource sharing
