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arginine vasopressin (neurophysin II, antidiuretic hormone, diabetes insipidus, neurohypophyseal)
neurophysin II, Bos taurus
Identifiers
Symbol	AVP
Alt. symbols	ARVP
NCBI gene	551
HGNC	894
OMIM	192340
RefSeq	NM_000490
UniProt	P01185
Other data
Locus	Chr. 20p13
Search for Structures Swiss-model Domains InterPro

Neurophysin II is acarrier protein with a size of 19,687.3Da and is made up of adimer of two virtually identical chains ofamino acids. Neurophysin II is a cleavage product (formed by splitting of a compound molecule into a simpler one) of theAVP gene. It is a neurohypophysialhormone that is transported in vesicles withvasopressin, the other cleavage product, alongaxons, from magnocellular neurons of thehypothalamus to the posterior lobe of thepituitary. Although it is stored in neurosecretory granules with vasopressin and released with vasopressin into the bloodstream, its biological action is unclear. Neurophysin II is also known as a stimulator ofprolactin secretion.

Neurophysin II is a carrier protein for vasopressin (ADH). It is produced in the cell bodies of the paraventricular and supraoptic nuclei and transported to its site of release in the axon terminals of the posterior pituitary.Oxytocin, a hormone similar in structure to vasopressin, is analogously bound and transported byneurophysin I. Both hormones are nine residues long, and only differ by the amino acids at positions three and eight. Oxytocin possesses Ile-3 whereas vasopressin possesses Phe-3. Both Ile and Phe are hydrophobic amino acids and undergo analogous binding to neurophysins.

Neurophysin II is a dimer with each monomer consisting of two anti-parallel β-sheets. Each chain is identical with the exception of a single amino acid substitution (Chain 1 contains Lys-18, whereas chain 2 contains Ala-18). Each chain is 95 amino acids in length and binds a single oxytocin molecule.The amino acid sequence of Neurophysin II is:

NH₂ - Ala - Met - Ser - Asp - Leu - Glu - Leu - Arg - Gln - Cys - Leu - Pro - Cys - Gly - Pro - Gly - Gly - Lys - Gly - Arg - Cys - Phe - Gly - Pro - Ser - Ile - Cys - Cys - Ala - Asp - Glu - Leu - Gly - Cys - Phe - Val - Gly - Thr - Ala - Glu - Ala - Leu - Arg - Cys - Gln - Glu - Glu - Asn - Tyr - Leu - Pro - Ser - Pro - Cys - Gln - Ser - Gly - Gln - Lys - Ala - Cys - Gly - Ser - Gly - Gly - Arg - Cys - Ala - Ala - Phe - Gly - Val - Cys - Cys - Asn - Asp - Glu - Ser - Cys - Val - Thr - Glu - Pro - Glu - Cys - Arg - Glu - Gly - Phe - His - Arg - Arg - Ala - OH

(Disulfide - bridge: - 10-54; - 13-27; - 21-44; - 28-34; - 61-73; - 67-85; - 74-79)

Point mutations in the genes that encode arginine vasopressin and or its carrier protein neurophysin II underlie most cases of the familial, autosomal dominant disorderneurohypophyseal diabetes insipidus^[1] (also called hereditary hypothalamicdiabetes insipidus). This condition results from insufficientADH release into systemic circulation.

• Copeptin
• Neurophysins
• Neurophysin I

• Neurophysin+II at the U.S. National Library of MedicineMedical Subject Headings (MeSH)

• Genes on human chromosome 20

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