糖心TV Complexity Science Events
Complexity Centre and MathSys CDT events carry priority over room D1.07.
To book D1.07 please email Sheetal dot Sharma at warwick dot ac dot uk
Please note that your event booking is for D1.07 only. The adjacent common room is a private area for the MathSys Centre that cannot used as part of your booking.
Complexity Forum: Philip Greulich (Edinburgh)
Speaker: Philip Greulich (School of Physics and Astronomy, University of Edinburgh)
Title: Buffering in traffic-like multi-track systems with finite particle reservoir: A regulation mechanism for protein production?
Abstract:
n particle transport systems on narrow tracks, bottlenecks can induce particle queues or traffic jams due to the confined geometry and mutual obstruction of particles. In this talk I will show that in the case of a finite reservoir of particles, the emergence of traffic jams can 'buffer' the particle reservoir: When parameters are varied, particle queues can absorb any variations in the reservoir.
This has interesting implications in particular when many tracks with different properties, like different particle entry and exit rates, compete for a finite reservoir. In particular it turns out that the current carried by a single track contains the full information about the entire distribution of the track properties in the system. This also implies that a queueing transition on a single track can indeed buffer the particle current on all other tracks.
The situation is biologically motivated by protein production in cells: A finite number of ribosomes is distributed among many different mRNA strands. Proteins are produced by the ribosomes proceeding along mRNAs from one end to the other, while ribosomes can mutually obstruct each other on crowded mRNAs. The genetic sequences of mRNAs and the abundance of sequence-specific tRNAs determine ribosome velocities, including some slow parts ('slow codons') that act as bottlenecks and induce ribosomal queuing. We have tested the buffering mechanism on a model for protein production taking real mRNA sequences and tRNA abundances from the budding yeast genome. In the case of highly abundant mRNAs of single genes, the buffering effect is reproduced.
The buffering effect may protect protein production levels from variations in external parameters and could be highly relevant, e.g. for biotechnology, if large amounts of proteins need to be produced. In that case the sudden drop of the free ribosome concentration due to overproduction of a single protein, leading to a crash of cell functions, could be buffered by the here stated effect.
Lunch: Group 2