Beyond the gene: decoding alternative isoforms

Area of Science:

• Molecular Biology
• Genomics
• Proteomics

Background:

• Most human genes express multiple messenger RNA (mRNA) transcripts through mechanisms like alternative splicing.
• These transcripts can translate into various protein isoforms, but their collective impact on the human proteome has been debated.
• Functional significance of alternative protein isoforms is known, but their widespread role remains unclear.

Purpose of the Study:

• To investigate the extent to which alternative mRNA transcripts diversify the human proteome at the protein level.
• To assess the biochemical distinctness and disease association of these alternative protein isoforms.
• To advocate for a shift towards isoform-aware characterization in molecular studies.

Main Methods:

• Utilized long-read RNA sequencing for comprehensive transcript analysis.
• Employed sensitive proteomics techniques to detect and quantify protein isoforms.
• Applied high-throughput methods to perturb and study individual isoform functions.

Main Results:

• Evidence suggests most alternative mRNA transcripts are translated into distinct protein isoforms at the protein level.
• These protein isoforms exhibit biochemical differences.
• A significant association between alternative protein isoforms and various diseases was observed.

Conclusions:

• Alternative protein isoforms play a substantial role in diversifying the human proteome.
• Technological advancements confirm the prevalence and functional relevance of protein isoforms.
• Future molecular characterization should adopt an 'isoform-aware' perspective, moving beyond single-gene analysis.