Figure 1. Tinkering with Transfer RNA.

Type 2 diabetes is associated with variant CDKAL1. Wei et al.⁴ recently ascribed a function to this gene: it critically modifies a specific transfer RNA (tRNA) by catalyzing the addition of a methyl–thio moiety (ms²t⁶) to a residue adjacent to the anticodon (in pink). Mice deficient in beta-cell Cdkal1 incorporate fewer lysine residues into proinsulin, which may contribute to the susceptibility of these mice to type 2 diabetes.