C7, a novel nucleolar protein, is the mouse homologue of the Drosophila late puff product L82 and an isoform of human OXR1

The C7 gene was identified in a project aimed to characterize differential gene expression upon attachment of cells to extracellular matrix proteins i n vitro. C7 is the homologue of Drosophila L82, a late puff gene (Stowers e t al. (1999) Dev. Biol. 213, 116-130) and human OXR1, a gene, which protect s cells against oxidation (Volkert et al. (2000) Proc. Natl. Acad. Sci. USA 97, 14530-14535). All are transcribed into multiple splice forms with a co mmon 3' domain. Additional members of this novel gene family are found in a number of eukaryotic species. In the mouse, the C7 gene is highly and broa dly expressed during development in at least 4 splice forms, 3 of which wer e sequenced. In the adult, the C7 gene is most highly expressed in brain an d testis. Antibodies to recombinant C7 protein localized to nucleoli in a v ariety of cell types, suggesting that C7 may be involved in the formation o r function of this important organelle. (C) 2001 Academic Press.