Neurophysin I

Neurophysin I is a carrier protein with a size of 10 KDa and containing 90 to 97 aminoacids that transports neurohypophysial hormones along axons, from the hypothalamus to the posterior lobe of the pituitary. This protein is necessary to prevent diffusion of peptide hormones out of the axons. Hormones of the posterior lobe of the pituitary are synthesized in hypothalamic nuclei and are packaged in secretory granules with their respective neurophysins.

Neurophysin I binds oxytocin for transport through the long axon originating in the paraventricular nucleus in the hypothalamus going to the neurohypophysis of the pituitary.

Neurofisina I