Loss of ncm⁵ and mcm⁵ wobble uridine side chains results in an altered metabolic profile

The Elongator complex, comprising six subunits (Elp1p-Elp6p), is required for formation of 5-carbamoylmethyl (ncm⁵) and 5-methoxycarbonylmethyl (mcm⁵) side chains on wobble uridines in 11 out of 42 tRNA species in Saccharomyces cerevisiae. Loss of these side chains reduces the efficiency of tRNA decoding during translation, resulting in pleiotropic phenotypes. Overexpression of hypomodified [Formula: see text], which in wild-type strains are modified with mcm⁵s²U, partially suppress phenotypes of an elp3Δ strain.

To identify metabolic alterations in an elp3Δ strain and elucidate whether these metabolic alterations are suppressed by overexpression of hypomodified [Formula: see text].

Metabolic profiles were obtained using untargeted GC-TOF-MS of a temperature-sensitive elp3Δ strain carrying either an empty low-copy vector, an empty high-copy vector, a low-copy vector harboring the wild-type ELP3 gene, or a high-copy vector overexpressing [Formula: see text]. The temperature sensitive elp3Δ strain derivatives were cultivated at permissive (30 °C) or semi-permissive (34 °C) growth conditions.

Culturing an elp3Δ strain at 30 or 34 °C resulted in altered metabolism of 36 and 46 %, respectively, of all metabolites detected when compared to an elp3Δ strain carrying the wild-type ELP3 gene. Overexpression of hypomodified [Formula: see text] suppressed a subset of the metabolic alterations observed in the elp3Δ strain.

Our results suggest that the presence of ncm⁵- and mcm⁵-side chains on wobble uridines in tRNA are important for metabolic homeostasis.