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

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 Enhancer 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 mutation of the Grg gene was constructed by gene targeting. Mice homozygous for this mutation completed embryogenesis and were born, but exhibited 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 Grg null mutation. (C) 1995 Wiley-Liss, Inc.