proteasotype

Proteasotype is a term used to describe the complete set of proteins and proteoforms expressed by a cell, tissue, organ, or organism at a given time and under specific conditions. It is intended to capture the dynamic protein complement that underpins cellular function, extending beyond the gene sequence to include protein abundance, isoforms, and post-translational modifications.

The concept is analogous to genotype and phenotype but operates at the proteome level. A proteasotype reflects which proteins are present, in what quantities, where they are localized, and which proteoforms arise from processes such as alternative splicing, proteolytic processing, and post-translational modifications. Because protein expression is highly context-dependent and changes with development, environment, disease, and treatment, the proteasotype is inherently dynamic.

Measurement and analysis rely on proteomics technologies. Mass spectrometry-based approaches, including data-independent acquisition and multiplexed quantification, provide broad and quantitative views of proteoforms. Complementary methods such as targeted assays and antibody-based platforms can increase sensitivity for specific proteins. Single-cell proteomics is advancing the ability to define proteasotypes at cellular resolution, while integrative analyses combine proteasomic data with genomics and transcriptomics to map functional states.

Applications of the proteasotype concept include biomarker discovery, characterization of cell states, assessment of disease progression, and evaluation of drug responses. Challenges remain, including the proteome’s complexity, coverage gaps for low-abundance proteins and many PTMs, standardization of definitions, and robust cross-study data integration. See also proteome, proteoform, and proteomics.