Proteome-wide copy-number estimation from transcriptomics.

It is easier to quantify mRNA in cells than it is to quantify protein, but proteins are what execute most cellular functions. Even though protein is synthesized from mRNA in cells, relating a cellular quantity of mRNA to a quantity of protein is challenging. Here, we bring together quantitative measures of mRNA and protein for 4366 genes in 369 different cultured cell types to build equations that predict protein abundance from the abundance of mRNAs expressed. These equations capture facets of biological regulation and work better than existing alternatives that rely on consensus values or ratios. Since mRNA measurements are more widespread than protein, this study makes new analyses possible by protein estimation from mRNA.