OXT Gene: Oxytocin/Neurophysin I Prepropeptide – Function, Mutations & Disease

The OXT gene encodes a precursor protein that is cleaved to produce oxytocin and neurophysin I. Oxytocin is a neuropeptide hormone primarily synthesized in the hypothalamus and released from the posterior pituitary. It plays critical roles in parturition, lactation, social bonding, pair bonding, maternal behavior, and modulation of anxiety and stress. Neurophysin I serves as a carrier protein for oxytocin during axonal transport. Dysregulation of OXT expression or signaling is associated with autism spectrum disorder, social anxiety, postpartum depression, and chronic pain conditions.

Tissue Expression

Cell Line Expression

Hotspot Mutations

Mutation functional classification

• Oxytocin signaling pathway (KEGG: hsa04921)

• Neuroactive ligand-receptor interaction (KEGG: hsa04080)

• cAMP signaling pathway (KEGG: hsa04024)

The OXT gene encodes a 125-amino-acid precursor preproprotein that is proteolytically processed to yield the mature oxytocin nonapeptide (CYIQNCPLG-NH2) and neurophysin I. Oxytocin is stored in secretory vesicles of the posterior pituitary and released into circulation upon neuronal stimulation. It acts via the oxytocin receptor (OXTR), a G-protein-coupled receptor, to regulate uterine contraction during labor, milk ejection during lactation, and central nervous system functions including social bonding, trust, and empathy. Neurophysin I binds oxytocin and facilitates its transport and storage. The mature oxytocin sequence is identical across most mammals, underscoring its evolutionary conservation.