Protein accounting in the cellular economy

Abstract

Knowing the copy number of cellular proteins is critical for understanding cell physiology. By being able to measure the absolute synthesis rates of the majority of cellular proteins, Li et al. gain insights into key aspects of translation regulation and fundamental principles of cellular strategies to adjust protein synthesis according to the functional needs.

Figure 1. Optimizing the Rates of Protein Synthesis

(A) Measurement of the absolute rates of protein synthesis shows that the expression of genes in polycistronic operons coding for stable multisubunit protein complexes is usually proportional to the subunit composition of the complex. (B) The protein abundance data reveal that the rate of MetE production is optimized to achieve the most favorable balance between active expression of the MetE enzyme and sufficient translation capacity for synthesizing the rest of the cellular proteins.