title: Characterization of the receptor for insulin-like growth factor on Leishmania promastigotes.
abstract: Insulin-like growth factor (IGF)-I constitutively present in the skin is one of the first growth factors that Leishmania parasites encounter after transmission to the vertebrate host. We have previously shown that IGF-I is a potent growth-promoting factor for Leishmania parasites. IGF-I binds specifically to a single-site putative receptor at the parasite membrane, triggering a cascade of phosphorylation reactions. In the present article we characterize the receptor for IGF-I on Leishmania (Leishmania) mexicana promastigotes. The receptor is a monomeric glycoprotein with a molecular mass of 65 kDa and is antigenically related to the alpha chain of human type 1 IGF-I receptor. Upon IGF-I stimulation the receptor undergoes autophosphorylation on tyrosine residues with activation of its signaling pathway. Activation of the IGF-I receptor also leads to phosphorylation of an 185-kDa molecule that is homologous to the substrate of the insulin receptor present in human cells, the insulin receptor substrate 1 (IRS-1).
authors.affiliation: Laboratory of Pathology of Infectious Diseases, Department of Pathology, University of Sao Paulo, Brazil. gomescla@usp.br
authors.forename: C M
authors.initials: CM
authors.lastname: Gomes
authors.forename: H
authors.initials: H
authors.lastname: Goto
authors.forename: A C
authors.initials: AC
authors.lastname: Magnanelli
authors.forename: H P
authors.initials: HP
authors.lastname: Monteiro
authors.forename: R P
authors.initials: RP
authors.lastname: Soares
authors.forename: C E
authors.initials: CE
authors.lastname: Corbett
authors.forename: M
authors.initials: M
authors.lastname: Gidlund
mesh_terms: D000818:Animals; D002846:Chromatography, Affinity; D002850:Chromatography, Gel; D007894:Leishmania mexicana / Q000378:metabolism*; D008970:Molecular Weight; D010766:Phosphorylation; D011233:Precipitin Tests; D017451:Receptors, Somatomedin / Q000737:chemistry* / Q000276:immunology / Q000378:metabolism
chemical_list: D017451:Receptors, Somatomedin