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* Neurohypophysial hormones signature *
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Oxytocin (or  ocytocin)  and  vasopressin  [1]  are  small  (nine  amino  acid
residues), structurally  and  functionally  related   neurohypophysial peptide
hormones. Oxytocin  causes  contraction of the smooth muscle of the uterus and
of the mammary gland while vasopressin has a direct antidiuretic action on the
kidney  and also  causes  vasoconstriction of the   peripheral vessels.   Like
the  majority of  active peptides,  both hormones  are  synthesized  as larger
protein  precursors  that are  enzymatically converted  to their mature forms.
Peptides belonging to  this family are also found in birds, fish, reptiles and
amphibians  (mesotocin,   isotocin,   valitocin,   glumitocin,    aspargtocin,
vasotocin) and have  also been found in locust [2] (neuropeptide F1/F2) and in
a mollusc [3] (conopressins G and S).

The pattern developed  to detect this category  of peptides spans their entire
sequence and includes five invariant amino acid residues.

-Consensus pattern: C-[LIFY](2)-x-N-C-P-x-G
                    [The two C's are linked by a disulfide bond].
-Sequences known to belong to this class detected by the pattern: ALL.
-Other sequence(s) detected in SWISS-PROT: NONE.
-Last update: June 1994 / Text revised.

[ 1] Acher R., Chauvet J.
     Biochimie 70:1197-1207(1988).
[ 2] Proux J.P., Miller C.A., Li J.P., Carney R.L., Girardie A., Delaage M.,
     Schooley D.A.
     Biochem. Biophys. Res. Commun. 149:180-186(1987).
[ 3] Cruz L.J., de Santos V., Zafaralla G.C., Ramilo C.A., Zeikus R.,
     Gray W.R., Olivera B.M.
     J. Biol. Chem. 262:15281-15284(1987).