Diversification of the insulin receptor family in the helminth parasite Schistosoma mansoni.
Insulin signalling is a very ancient and well conserved pathway in metazoan cells, dependent on insulin receptors (IR) which are transmembrane proteins with tyrosine kinase activity. A unique IR is usually present in invertebrates whereas two IR members are found with different functions in vertebrates. This work demonstrates the existence of two distinct IR homologs (SmIR-1 and SmIR-2) in the parasite trematode Schistosoma mansoni. These two receptors display differences in several structural motifs essential for signalling and are differentially expressed in parasite tissues, suggesting that they could have distinct functions. The gene organization of SmIR-1 and SmIR-2 is similar to that of the human IR and to that of the IR homolog from Echinococcus multilocularis (EmIR), another parasitic platyhelminth. SmIR-1 and SmIR-2 were shown to interact with human pro-insulin but not with pro-insulin-like growth factor-1 in two-hybrid assays. Phylogenetic results indicated that SmIR-2 and EmIR might be functional orthologs whereas SmIR-1 would have emerged to fulfil specific functions in schistosomes.
Khayath
Naji
N
U547 INSERM, Institut Pasteur de Lille, Lille Cedex, France.
Vicogne
Jerome
J
Ahier
Arnaud
A
BenYounes
Amena
A
Konrad
Christian
C
Trolet
Jacques
J
Viscogliosi
Eric
E
Brehm
Klaus
K
Dissous
Colette
C
D000595:Amino Acid Sequence; D000818:Animals; D015153:Blotting, Western; D003001:Cloning, Molecular; D005260:Female; D018507:Gene Expression Regulation, Developmental; D015801:Helminth Proteins / Q000235:genetics* / Q000378:metabolism; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008856:Microscopy, Fluorescence; D008969:Molecular Sequence Data; D020033:Protein Isoforms / Q000235:genetics / Q000378:metabolism; D011972:Receptor, Insulin / Q000235:genetics* / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012550:Schistosoma mansoni / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D020798:Two-Hybrid System Techniques
D015801:Helminth Proteins; D020033:Protein Isoforms; D011972:Receptor, Insulin