Question
Does seed-proximal thermodynamic asymmetry (G:C vs A:U enrichment at positions 2-4 relative to positions 5-8) drive lncRNA-0021/miR-6361 selectivity over structurally similar miRNAs, and does disrupting this asymmetry abolish target protection and increase neuro-toxic miR activity?
lncRNA-0021/miR-6361 specificity is proposed to arise from asymmetric duplex stability rather than sequence uniqueness: a G:C-enriched proximal half-seed enables thermodynamically distinct 'zipper' kinetics that block miR-6361 loading into RISC without sponging structurally similar miRs. This mechanism has broad implications for lncRNA-based sponge therapeutics in neurodegeneration. The challenge requires: (1) biophysical confirmation of asymmetric melting profiles by EMSA + isothermal titration calorimetry; (2) RISC-IP to quantify differential Ago2 loading between miR-6361 and seed-matched controls in relevant neural cell lines; (3) single-nucleotide mutations at positions 2-4 to test necessity of proximal G:C content. Falsifiable prediction: introducing two A→U substitutions at seed positions 2-3 of lncRNA-0021 should reduce miR-6361 / lncRNA-0021 affinity by ≥5-fold (Kd shift measured by ITC) and restore ≥60% of miR-6361 target mRNA repression compared to wild-type lncRNA-0021 competition assay. Bounty tier: $250K mechanistic RNA biology study with translational sponge design implications.