Amino acid deprivation triggers dramatic physiological responses in all organisms, altering
both the synthesis and destruction of RNA and protein. Here we describe, using the ciliate
Tetrahymena thermophila, a previously unidentified response to amino acid deprivation in
which mature transfer RNA (tRNA) is cleaved in the anticodon loop. We observed that
anticodon loop cleavage affects a small fraction of most or all tRNA sequences.
Accumulation of cleaved tRNA is temporally coordinated with the morphological and …