Insulin family signature
The insulin family of proteins [
1] groups a number of active peptides which
are evolutionary related. This family currently consists of:
Insulin-like growth factors I and II (IGFs or somatomedins) [
Mammalian Leydig cell-specific insulin-like peptide (Ley-I-L) (gene INSL3)
Mammalian early placenta insulin-likepeptide (ELIP) (gene INSL4) [
Insulin-like peptide 5 (gene INSL5).
Insect prothoracicotropic hormone (PTTH) (bombyxin) [
Locust insulin-related peptide (LIRP) [
Molluscan insulin-related peptides 1 to 5 (MIP) [
Caenorhabditis elegans insulin-like peptides [
Structurally, all these peptides consist of two polypeptide chains (A and B)
linked by two disulfide bonds.
B chain xxxxxxCxxxxxxxxxxxxCxxxxxxxxx
A chain xxxxxCCxxxCxxxxxxxxCx
'C': conserved cysteine involved in a disulfide bond.
'*': position of the pattern.
As shown in the schematic representation above, they all share a conserved
arrangement of four cysteines in their A chain. The first of these cysteines
is linked by a disulfide bond to the third one and the second and fourth
cysteines are linked by interchain disulfide bonds to cysteines in the B
chain. As a pattern for this family of proteins, we have used the region
which includes the four conserved cysteines in the A chain.
December 2004 / Pattern and text revised.
PROSITE method (with tools and information) covered by this documentation:
PS00262; Insulin family signature (PATTERN)
1 Authors Blundell T.L. Humbel R.E.
Title Hormone families: pancreatic hormones and homologous growth factors.
Source Nature 287:781-787(1980).
PubMed ID 6107857
2 Authors Humbel R.E.
Title Insulin-like growth factors I and II.
Source Eur. J. Biochem. 190:445-462(1990).
PubMed ID 2197088
3 Authors Adham I.M. Burkhardt E. Benahmed M. Engel W.
Title Cloning of a cDNA for a novel insulin-like peptide of the testicular Leydig cells.
Source J. Biol. Chem. 268:26668-26672(1993).
PubMed ID 8253799
4 Authors Chassin D. Laurent A. Janneau J.-L. Berger R. Bellet D.
Title Cloning of a new member of the insulin gene superfamily (INSL4) expressed in human placenta.
Source Genomics 29:465-470(1995).
PubMed ID 8666396
5 Authors Nagasawa H. Kataoka H. Isogai A. Tamura S. Suzuki A. Mizoguchi A. Fujiwara Y. Suzuki A. Takahashi S.Y. Ishizaki H.
Source Proc. Natl. Acad. Sci. U.S.A. 83:5480-5483(1986).
6 Authors Lagueux M. Lwoff L. Meister M. Goltzene F. Hoffmann J.A.
Title cDNAs from neurosecretory cells of brains of Locusta migratoria (Insecta, Orthoptera) encoding a novel member of the superfamily of insulins.
Source Eur. J. Biochem. 187:249-254(1990).
PubMed ID 1688797
7 Authors Smit A.B. Geraerts W.P.M. Meester I. van Heerikhuizen H. Joosse J.
Title Characterization of a cDNA clone encoding molluscan insulin-related peptide II of Lymnaea stagnalis.
Source Eur. J. Biochem. 199:699-703(1991).
PubMed ID 1868853
8 Authors Duret L. Guex N. Peitsch M.C. Bairoch A.
Title New insulin-like proteins with atypical disulfide bond pattern characterized in Caenorhabditis elegans by comparative sequence analysis and homology modeling.
Source Genome Res. 8:348-353(1998).
PubMed ID 9548970
9 Authors Robitzki A. Schroder H.C. Ugarkovic D. Pfeifer K. Uhlenbruck G. Muller W.E.G.
Title Demonstration of an endocrine signaling circuit for insulin in the sponge Geodia cydonium.
Source EMBO J. 8:2905-2909(1989).
PubMed ID 2531072
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