PROTEIN CHARACTERIZATION AND TARGETED DISRUPTION OF GRG, A MOUSE GENE-RELATED TO THE GROUCHO TRANSCRIPT OF THE DROSOPHILA ENHANCER OF SPLITCOMPLEX

The Grg gene encodes a 197 amino acid protein homologous to the amino- terminal domain of the product of the groucho gene of the Drosophila E nhancer of split complex. Analysis with a polyclonal antisera specific for the Grg protein revealed that Grg is a 25 kd nuclear protein that can participate in specific protein-protein interactions, A null muta tion of the Grg gene was constructed by gene targeting. Mice homozygou s for this mutation completed embryogenesis and were born, but exhibit ed varying degrees of postnatal growth deficiency. No dosage-sensitive genetic interaction was detected between the Notch1 and Grg genes in mice heterozygous for a Notch1 mutant allele and homozygous for the Gr g null mutation. (C) 1995 Wiley-Liss, Inc.