Loss of function effect of RET mutations causing Hirschsprung disease.
We have introduced three Hirschsprung (HSCR) mutations localized in the tyrosine kinase domain of RET into the RET/PTC2 chimaeric oncogene which is capable of transforming NIH3T3 mouse fibroblasts and of differentiating pC12 rat pheochromocytoma cells. The three HSCR mutations abolished the biological activity of RET/PTC2 in both cell types and significantly decreased its tyrosine phosphorylation. By contrast, a rare polymorphism in exon 18 does not alter the transforming capability of RET/PTC2 or its tyrosine phosphorylation. These data suggest a loss of function effect of HSCR mutations which might act through a dominant negative mechanism. Our model system is therefore capable of discriminating between causative HSCR mutations and rare polymorphisms in the tyrosine kinase domain of RET.
Pasini
B
B
Laboratorio di Genetica Molecolare, Istituto Giannina Gaslini, Genova Quarto, Italy.
Borrello
M G
MG
Greco
A
A
Bongarzone
I
I
Luo
Y
Y
Mondellini
P
P
Alberti
L
L
Miranda
C
C
Arighi
E
E
Bocciardi
R
R
D016475:3T3 Cells; D000818:Animals; D001483:Base Sequence; D002454:Cell Differentiation; D002471:Cell Transformation, Neoplastic; D017868:Cyclic AMP-Dependent Protein Kinases / Q000235:genetics / Q000378:metabolism*; D029721:Drosophila Proteins; D005091:Exons; D005816:Genetic Complementation Test; D006367:HeLa Cells; D006627:Hirschsprung Disease / Q000235:genetics*; D006801:Humans; D051379:Mice; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D009154:Mutation; D016716:PC12 Cells; D010766:Phosphorylation; D011233:Precipitin Tests; D011518:Proto-Oncogene Proteins / Q000235:genetics / Q000502:physiology*; D051096:Proto-Oncogene Proteins c-ret; D051381:Rats; D020794:Receptor Protein-Tyrosine Kinases / Q000235:genetics / Q000502:physiology*; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000502:physiology; D014162:Transfection; D014443:Tyrosine / Q000378:metabolism
D029721:Drosophila Proteins; D011518:Proto-Oncogene Proteins; D011993:Recombinant Fusion Proteins; D014443:Tyrosine; D051096:Proto-Oncogene Proteins c-ret; D020794:Receptor Protein-Tyrosine Kinases; C416649:Ret protein, Drosophila; C494999:Ret protein, mouse; C495001:Ret protein, rat; D017868:Cyclic AMP-Dependent Protein Kinases