Methoprene-tolerant protein (Juvenile hormone receptor) (Met)

The Methoprene-tolerant protein (Met) is the primary receptor for juvenile hormone (JH), a sesquiterpenoid that regulates essential aspects of insect development, metamorphosis, and reproduction (Jindra et al., 2013, Annual Review of Entomology). As a member of the basic helix-loop-helix-Per-Arnt-Sim (bHLH-PAS) family of transcription factors, Met binds JH and subsequently interacts with the co-activator Taiman to regulate the transcription of JH-responsive genes, such as Krüppel homolog 1 (Charles et al., 2011, PNAS). This signaling pathway is critical for maintaining the insect in a juvenile state and preventing premature metamorphosis (Bitra et al., 2012, Journal of Biological Chemistry). Because the JH signaling pathway is unique to arthropods and absent in vertebrates, it serves as a highly specific target for insect growth regulators (IGRs) like methoprene and pyriproxyfen (PubChem). These compounds act as JH mimics, disrupting the life cycle of pests and disease vectors, such as mosquitoes and fleas, making them valuable tools in public health and agriculture (WHO, 2021). Metamorphosis disruption via this receptor prevents the emergence of reproductive adults, effectively controlling population growth of harmful species. The specificity of this receptor to insects minimizes the risk of direct toxicity to humans and other mammals, although environmental impacts on other arthropods remain a concern (EPA, 2010).

Other names

Juvenile hormone receptorJH receptorMethoprene-tolerantMet protein

Juvenile hormone mimics act as agonists of the Methoprene-tolerant protein, binding to the receptor's PAS-B domain to induce the formation of a heterodimer with the Taiman co-activator; this complex then binds to juvenile hormone response elements (JHREs) to activate genes like Kr-h1, which inhibits metamorphosis and disrupts reproductive development (Jindra et al., 2015, Annual Review of Entomology; Wen et al., 2015, PNAS).