The human GRB2 and Drosophila Drk genes can functionally replace the Caenorhabditis elegans cell signaling gene sem-5.
Mutations in the Caenorhabditis elegans gene sem-5 affect cell signaling processes involved in guiding a class of cell migrations and inducing vulval cell fates. The sem-5 sequence encodes a protein comprised almost exclusively of SH2 and SH3 domains (SH, src homology region) that are found together in many signaling proteins and nonreceptor tyrosine kinases. A human protein, GRB2, was identified by its ability to associate with the activated human epidermal growth factor receptor (hEGFR). The GRB2 and Sem-5 proteins share an identical architecture of their SH2 and SH3 domains and 58% amino acid sequence identity. Here we demonstrate that GRB2 and a Drosophila sem-5-like gene Drk can specifically rescue sem-5 mutants. We also show that Sem-5, like GRB2, can bind to the activated hEGFR in vitro. We further correlate the abilities of several mutant variants of GRB2 and Sem-5 to bind to the hEGFR in vitro with their abilities to functionally replace sem-5 in vivo. These data indicate that GRB2 and Drk are functional homologues of Sem-5 and demonstrate the high degree of conservation of both structure and function between signaling systems throughout evolution.
Stern
M J
MJ
Department of Genetics, Yale University School of Medicine, New Haven, Connecticut 06520-8005.
Marengere
L E
LE
Daly
R J
RJ
Lowenstein
E J
EJ
Kokel
M
M
Batzer
A
A
Olivier
P
P
Pawson
T
T
Schlessinger
J
J
D048868:Adaptor Proteins, Signal Transducing; D000818:Animals; D030801:Animals, Genetically Modified; D001483:Base Sequence; D017173:Caenorhabditis elegans / Q000235:genetics*; D029742:Caenorhabditis elegans Proteins; D003001:Cloning, Molecular; D029721:Drosophila Proteins; D066246:ErbB Receptors / Q000032:analysis / Q000235:genetics* / Q000378:metabolism; D005260:Female; D051380:GRB2 Adaptor Protein; D017238:Genes, Helminth; D017344:Genes, Insect / Q000235:genetics; D015801:Helminth Proteins / Q000235:genetics*; D006801:Humans; D007301:Insect Hormones / Q000235:genetics*; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D017354:Point Mutation / Q000235:genetics; D011506:Proteins / Q000235:genetics*; D017479:Receptors, Platelet-Derived Growth Factor / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000302:isolation & purification; D015398:Signal Transduction / Q000235:genetics*; D014170:Transformation, Genetic; D014844:Vulva / Q000254:growth & development
D048868:Adaptor Proteins, Signal Transducing; D029742:Caenorhabditis elegans Proteins; D029721:Drosophila Proteins; D051380:GRB2 Adaptor Protein; C495948:GRB2 protein, human; D015801:Helminth Proteins; D007301:Insect Hormones; D011506:Proteins; D011993:Recombinant Fusion Proteins; C085751:Sem-5 protein, C elegans; C080530:drk protein, Drosophila; D066246:ErbB Receptors; D017479:Receptors, Platelet-Derived Growth Factor