Provided herein are synthetic nucleic acid molecules and methods of using such synthetic nucleic acid molecules for strong repression of target gene expression. In particular, provided herein are methods for altering expression of a protein in a cell, where the method comprises introducing into a cell a protein coding sequence operably linked to a near-threshold translational repressor having first and second trigger recognition sequences that are fully or partially complementary to a repressing trigger RNA; and introducing into a cell the repressing trigger RNA.