Structure of the gene for a carbohydrate-binding receptor unique to rat kupffer cells

Abstract

The gene encoding the rat Kupffer cell receptor for fucose and galactose (Lehrman, M. A., and Hill, R. L. (1986) J. Biol. Chem. 261, 7419-7425 and Lehrman, M. A., Haltiwanger, R. S., and Hill, R. L. (1986) J. Biol. Chem. 261, 7426-7432) has been isolated and characterized. The nucleotide sequence of the 9.7-kilobase gene and of 1 kilobase of 5'-flanking sequence was determined. The 5' end of the receptor coding sequence was determined by primer extension and S1 mapping of the receptor transcript. Knowledge of the transcription start site and the 5'-flanking sequence allowed potential promoter elements to be identified. The Kupffer cell receptor coding sequence is encoded by seven exons that are split by six introns. The divisions among domains in the receptor can be correlated with divisions among exons in the gene. The carbohydrate recognition domain is encoded by three exons similar to those in the rat hepatic lectin, human Fc receptor for IgE, and rat cartilage proteoglycan core protein genes. A model for the evolution of the vertebrate lectin genes that have been analyzed is presented.