Analysis of human upstream open reading frames and impact on gene expression

Area of Science:

• Molecular Biology
• Genetics
• Bioinformatics

Background:

• Upstream open reading frames (uORFs) are regulatory elements in 5' untranslated regions (5'UTRs) controlling main open reading frame (mORF) translation.
• Dysregulated uORF activity is implicated in genetic disorders.
• A systematic investigation into patient variations and uORF status was lacking.

Purpose of the Study:

• To systematically examine the impact of uORFs on human transcripts.
• To investigate the relationship between genetic variations, uORF status, and gene expression.
• To identify disease-associated mutations affecting uORF function.

Main Methods:

• Analysis of gene ontology (GO) annotations and sequence features.
• Examination of human transcript datasets.
• Screening of disease variation databases (3,740,225 variations).
• Experimental validation of identified mutations.

Main Results:

• uORF-containing genes are enriched in functions like oncogenes and transcription factors.
• uORFs influence translation initiation site (TIS) determination.
• Genes with uORFs exhibit lower protein expression levels across human tissues.
• Identified uORF-altering mutations suspected to alter gene expression levels.
• Experimental validation confirmed mutations significantly impacting protein expression with modest transcriptional changes.

Conclusions:

• uORFs play a significant role in modulating protein expression in human genes.
• uORF-altering mutations are identified in human variation data and linked to altered protein levels.
• These findings offer new insights into the role of mutations in disease pathogenesis.