A SNP uncoupling Mina expression from the TGFβ signaling pathway.

Area of Science:

• Genetics
• Molecular Biology
• Immunology

Background:

• Mina, a JmjC family 2-oxoglutarate oxygenase, has diverse roles in cell proliferation, cancer, T cell differentiation, inflammation, and parasite expulsion.
• Transcriptional regulation of Mina is not well understood, despite its varied expression.
• Heritable differences in Mina protein levels across mouse strains correlate with specific genetic variations in its promoter/intron 1 region.

Purpose of the Study:

• To investigate the hypothesis that single nucleotide polymorphisms (SNPs) in the Mina promoter/intron 1 region affect cis-regulatory elements (CREs).
• To identify and functionally validate CREs within the Mina locus that contribute to heritable differences in Mina expression.

Main Methods:

• Comprehensive scanning for CREs across a 26-kilobase genomic interval of the Mina locus.
• Functional validation of identified CREs.
• Analysis of SNP effects on transcription factor binding (Smad3) and pathway responsiveness (TGFβ).

Main Results:

• Eight potential CREs were identified within the Mina locus.
• Four CREs were functionally validated, with one strong CRE (E2) in intron 1 showing significant results.
• A specific SNP within the E2 CRE altered Smad3 binding and abolished transforming growth factor beta (TGFβ) responsiveness in a strain-dependent manner (BALB/c vs. C57Bl/6).

Conclusions:

• The transforming growth factor beta (TGFβ) signaling pathway is crucial for regulating Mina expression.
• SNP rs4191790 is identified as a key determinant of heritable variation in Mina expression levels.
• The findings raise questions about the evolutionary implications of an allele that decouples Mina expression from TGFβ signaling.