The causes of protein evolutionary rate variation

Area of Science:

• Molecular Biology
• Evolutionary Biology
• Genetics

Background:

• The rate of protein evolution exhibits over a 1000-fold variation.
• For three decades, protein function was considered the primary determinant of evolutionary rate.
• Previous models did not fully account for the variability in protein evolutionary rates.

Purpose of the Study:

• To identify the key factor influencing the rate of protein evolution in yeast.
• To challenge the established paradigm linking protein evolutionary rate solely to protein function.
• To investigate the role of gene expression and protein abundance in evolutionary dynamics.

Main Methods:

• Analysis of protein abundance data in yeast.
• Examination of mRNA expression levels.
• Assessment of synonymous codon usage patterns.
• Correlation analysis between these factors and protein evolutionary rates.

Main Results:

• A single underlying factor, encompassing mRNA expression, protein abundance, and codon usage, was identified as the chief driver of protein evolutionary rate.
• This factor explained a significant portion of the variability previously attributed to protein function.
• The findings challenge the long-standing hypothesis that protein function is the sole determinant.

Conclusions:

• The study identifies a unifying factor regulating protein evolutionary rates in yeast.
• This finding suggests that gene expression and protein abundance are critical determinants of evolutionary speed.
• Further research is needed to ascertain if this rule applies universally across all biological systems.