Primary structure, genomic organization and expression of the major secretory protein of murine epididymis, ME1

The mouse cDNA and its genomic clones encoding the epididymal secretory gly coprotein ME1 were identified. The Me1 gene spans 15 kb with four exons and three introns. The deduced amino-acid sequence of the ME1 cDNA revealed th at it consists of 149 amino acid residues, which contain a signal peptide c haracteristic of secretory proteins. six cysteine residues and a proline-ri ch region conserved in the orthologous proteins. Northern blot analysis rev ealed that 1.3 kb ME1 mRNA is highly expressed in the mouse epididymis. The polyclonal antibodies generated against human HE1 (ME1 orthologous protein ) expressed in bacteria reacted with approximately 17 to 25 kDa components in mouse epididymis crude extract. The reduction of the molecular mass of t he recombinant ME1 protein with the digestion of glycopeptidase A indicated that it is modified by Asn-linked glycosylation. (C) 2000 Elsevier Science B.V. All rights reserved.