How cells make measurements
Topic
A fundamental problem of cell biology is to understand how cells make
measurements and then make behavioral decisions in response to these
measurements. The full answer to this question is not known but there
are some underlying principles that are coming to light. The short
answer is that the rate of molecular diffusion contains quantifiable
information that can be transduced by biochemical feedback to give
control over physical structures. In this talk, this principle will be
illustrated by two specific examples of how rates of molecular
diffusion contain information that is used to make a measurement and a
behavioral decision.
Example 1: Bacterial populations of P. aeruginosa are known to make a decision to secrete polymer gel on the basis of the size of the colony in which they live. This process is called quorum sensing and only recently has the mechanism for this been sorted out. It is now known that P. aeruginosa produces a chemical whose rate of diffusion out of the cell provides information about the size of the colony which when coupled with positive feedback gives rise to a hysteretic biochemical switch.
Example 2: Salmonella employ a mechanism that combines molecular diffusion with a negative feedback chemical network to
Example 1: Bacterial populations of P. aeruginosa are known to make a decision to secrete polymer gel on the basis of the size of the colony in which they live. This process is called quorum sensing and only recently has the mechanism for this been sorted out. It is now known that P. aeruginosa produces a chemical whose rate of diffusion out of the cell provides information about the size of the colony which when coupled with positive feedback gives rise to a hysteretic biochemical switch.
Example 2: Salmonella employ a mechanism that combines molecular diffusion with a negative feedback chemical network to
Speakers
Additional Information
MITACS Math Biology Seminar 2007
James Keener (University of Utah)
James Keener (University of Utah)