Protein Fluctuations in Single Cells and Population Variability

The copy number of any protein varies among cells even in a genetically homogenous 

population. This variation causes changes in the shape, structure and behavior of individuals 

within the population. Characterizing and understanding this variation and its sources is a 

fundamental problem in biophysics. In my talk I will discuss our recent results which show that 

the protein distribution measured under a broad range of biological realizations exhibit universal 

features that stem from the cellular dynamics that control protein expression. I will also show 

that the essential features of the universal distribution can be captured by a reduced 

characterization of the entire complexity of intra-generation processes using a single stochastic 

variable, namely the rate of exponential protein accumulation.