The yeast rapid tRNA decay pathway competes with elongation factor 1A for substrate tRNAs and acts on tRNAs lacking one or more of several modifications

A trm1-Δ tef1-Δ strain is subject to RTD of tRNA^Ser(CGA) and tRNA^Ser(UGA). (A) The temperature sensitivity of a trm1-Δ tef1-Δ strain is substantially suppressed by overproduction of tRNA^Ser(CGA) or tRNA^Ser(UGA). Wild-type and trm1-Δ tef1-Δ strains bearing [2μ LEU2 tRNA^Ser(CGA)], [2μ LEU2 tRNA^Ser(UGA)], or a plasmid vector control were grown overnight in SD-Leu media, serially diluted, plated on YPG media, and incubated for 3 d at the indicated temperatures. (B) trm1-Δ tef1-Δ mutants undergo more rapid degradation of tRNA^Ser(UGA) than trm1-Δ mutants. Strains were grown in YPG media to OD₆₀₀ 0.4 and shifted to 37°C, and RNA from cells was analyzed as described in Figure 1B. Diamonds indicate wild type; squares, trm1-Δ; and open triangles, trm1-Δ tef1-Δ.