Prothoracicotropic hormone (PTTH)

Prothoracicotropic hormone (PTTH) is a homodimeric neuropeptide that serves as the primary hormonal signal initiating molting and metamorphosis in insects (Rewitz et al., 2009). It is synthesized by specific neurosecretory cells in the insect brain and released into the hemolymph, where it acts on the prothoracic glands to stimulate the production of ecdysone, the precursor to the molting hormone 20-hydroxyecdysone (Mizoguchi et al., 2013). The secretion machinery involves complex regulatory inputs, including circadian rhythms and nutritional status, which ensure that developmental transitions occur under optimal conditions (McBrayer et al., 2007). PTTH exerts its effects by binding to the Torso receptor, a receptor tyrosine kinase, which activates the extracellular signal-regulated kinase (ERK) pathway (Yamanaka et al., 2010). While not a target for human medicine, the PTTH-Torso axis is a significant focus for the development of highly specific insect growth regulators and pest control strategies. Disrupting this machinery can lead to permanent developmental arrest, providing a mechanism to control agricultural pests and disease vectors without affecting non-arthropod species.

Other names

Brain hormoneActivation hormoneProthoracicotropic hormone secretion machineryPTTH-producing neurosecretory cells

Disruption of the PTTH-Torso signaling axis to inhibit ecdysteroidogenesis and arrest insect development (Rewitz et al., 2009).