title: Conservation of epidermal growth factor receptor function in the human parasitic helminth Schistosoma mansoni.
abstract: The epidermal growth factor receptor (EGF-R) plays an important role in development and cell differentiation, and homologues of EGF-R have been identified in a broad range of vertebrate and invertebrate organisms. This work concerns the functional characterization of SER, the EGF-R-like molecule previously identified in the helminth parasite Schistosoma mansoni. Transactivation assays performed in epithelial Madin-Darby canine kidney cells co-transfected with SER and a Ras-responsive reporter vector indicated that SER was able to trigger a Ras/ERK pathway in response to human epidermal growth factor (EGF). These results were confirmed in Xenopus oocytes showing that human EGF induced meiosis reinitiation characterized by germinal vesicle breakdown in SER-expressing oocytes. Germinal vesicle breakdown induced by EGF was dependent on receptor kinase activity and shown to be associated with phosphorylation of SER and of downstream ERK proteins. (125)I-EGF binding experiments performed on SER-expressing oocytes revealed high affinity (2.9 x 10(-9) M) of the schistosome receptor for human EGF. Phosphorylation of the native SER protein present in S. mansoni membranes was also shown to occur upon binding of human EGF. These data demonstrate the ability of the SER schistosome receptor to be activated by vertebrate EGF ligands as well as to activate the classical ERK pathway downstream, indicating the conservation of EGF-R function in S. mansoni. Moreover, human EGF was shown to increase protein and DNA synthesis as well as protein phosphorylation in parasites, supporting the hypothesis that host EGF could regulate schistosome development. The possible role of SER as a receptor for host EGF peptides and its implication in host-parasite signaling and parasite development are discussed.
authors.affiliation: Unité 547 INSERM, Institut Pasteur de Lille, 59019 Lille Cedex, France.
authors.forename: Jerome
authors.initials: J
authors.lastname: Vicogne
authors.forename: Katia
authors.initials: K
authors.lastname: Cailliau
authors.forename: David
authors.initials: D
authors.lastname: Tulasne
authors.forename: Edith
authors.initials: E
authors.lastname: Browaeys
authors.forename: Yu Tao
authors.initials: YT
authors.lastname: Yan
authors.forename: Veronique
authors.initials: V
authors.lastname: Fafeur
authors.forename: Jean Pierre
authors.initials: JP
authors.lastname: Vilain
authors.forename: Dominique
authors.initials: D
authors.lastname: Legrand
authors.forename: Jacques
authors.initials: J
authors.lastname: Trolet
authors.forename: Colette
authors.initials: C
authors.lastname: Dissous
mesh_terms: D000818:Animals; D001483:Base Sequence; D002460:Cell Line; D017931:DNA Primers; D004285:Dogs; D066246:ErbB Receptors / Q000502:physiology*; D006790:Host-Parasite Interactions; D010766:Phosphorylation; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012550:Schistosoma mansoni / Q000502:physiology*; D014981:Xenopus
chemical_list: D017931:DNA Primers; D066246:ErbB Receptors