Variability and memory of protein levels in human cells Sigal et al Nature 2006- 444-643-646
This paper looks at an important element of cell biology and hence metabolism and hence the influence of nutrition on metabolism and cell biology , that is the timescale over which protein concentrations mix in individual cells. Mixing meaning the time period over which cell lines reach the concentration that is characteristic of that cell. The authors looked at fluctuations over time of 20 endogenous proteins in living human cell tagged with a yellow fluorescent protein. Mixing between high and low concentrations occcured for all the proteins but the the levels of proteins from the same biological pathway fluctuated in more similar concentrations than other proteins in different pathways.
The random fluctuations in regulatory components are amplified as a signal cascade down a pathway. Alternatively long lived responses may result from feedback mechanisms.
- Martin Eastwood