Inosine biosynthesis in transfer RNA: A postulated role in immune regulation

A hypothesis is put forth describing a role in immune regulation for inosine biosynthesis in the anticodon of tRNA. The enzymatic insertion of hypoxanthine into the tRNA wobble base position is predicted to be a control point for the translation of proteins and peptides required for normal immune function. The substrate for inosine biosynthesis in tRNA, hypoxanthine, is an intermediate in the purine catabolic pathway, and defects in this pathway are associated with inherited immunodeficiency diseases. Therefore, a role for aberrant inosine biosynthesis in tRNA is postulated in causing the immunodeficient conditions, and it may be a relevant molecular defect in leukemia as well.