An extensible RNA-based framework for engineering ligand-controlled gene regulatory systems, called ribozyme switches, that exhibit tunable regulation, design modularity, and target specificity is provided. These switch platforms typically contain a sensor domain, comprised of an aptamer sequence, and an actuator domain, comprised of a hammerhead ribozyme sequence. A variety of modes of standardized information transmission between these domains can be employed, and this application demonstrates a mechanism that allows for the reliable and modular assembly of functioning synthetic hammerhead ribozyme switches and regulation of ribozyme activity in response to various effectors. In some embodiments aptamer-regulated cis-acting hammerhead ribozymes are provided.