PROSITE documentation PDOC00239
Somatotropin, prolactin and related hormones signatures


The hormone somatotropin (growth hormone, GH) which plays an important role in growth control, choriomammotropin (lactogen), a placental analog of GH; and prolactin which acts primarily on the mammary gland by promoting lactation, have been shown [1] to be homologous. This family of proteins also includes other hormones listed below (references are only provided for recently determined sequences).

  • Rodents placental lactogens I and II.
  • Bovine and sheep lactogen.
  • Mouse proliferin I, II, III and proliferin related protein [2].
  • Bovine placental prolactin-related proteins I, II, and III [3].
  • Rat placental prolactin-like proteins A and B.
  • Human growth hormone variants 1 (GH-V1) and 2 (GH-V2).
  • Somatolactin (SL) from various fish [4].

The schematic representation of the structure of proteins belonging to this family is shown below.

                     ***                          *****
                     |                            |   |  |
                     +----------------------------+   +--+
'C': conserved cysteine involved in a disulfide bond.
'*': position of the patterns.

We developed two signature patterns for this family of proteins, both patterns include cysteines involved in conserved disulfide bonds.

Last update:

April 2006 / Pattern revised.


Technical section

PROSITE methods (with tools and information) covered by this documentation:

SOMATOTROPIN_1, PS00266; Somatotropin, prolactin and related hormones signature 1  (PATTERN)

SOMATOTROPIN_2, PS00338; Somatotropin, prolactin and related hormones signature 2  (PATTERN)


1AuthorsWallis M.
TitleEpisodic evolution of protein hormones in mammals.
SourceJ. Mol. Evol. 53:10-18(2001).
PubMed ID11683318

2AuthorsConnor A.M. Waterhouse P. Khokha R. Denhardt D.T.
TitleCharacterization of a mouse mitogen-regulated protein/proliferin gene and its promoter: a member of the growth hormone/prolactin gene superfamily.
SourceBiochim. Biophys. Acta 1009:75-82(1989).
PubMed ID2790033

3AuthorsKessler M.A. Milosavljevic M. Zieler C.G. Schuler L.A.
TitleA subfamily of bovine prolactin-related transcripts distinct from placental lactogen in the fetal placenta.
SourceBiochemistry 28:5154-5161(1989).
PubMed ID2765528

4AuthorsRand-Weaver M. Noso T. Muramoto K. Kawauchi H.
SourceBiochemistry 30:1509-1515(1991).

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