MOLECULAR-CLONING AND CHARACTERIZATION OF A MOUSE OVIDUCT-SPECIFIC GLYCOPROTEIN

In the present study, we have isolated the cDNA for the mouse oviduct- specific glycoprotein (MOGP) by screening the mouse oviduct cDNA libra ry with the bovine oviduct-specific glycoprotein (BOGP)-cDNA probe and by the 5' rapid amplification of the cDNA end (5' RACE), The total le ngth of cDNA was determined to be 2525 base pairs (bp) by sequence ana lysis. The coding region contained 2163 bp translating to 721 amino ac ids. Based on comparisons with the N-terminal amino acid sequences of purified-BOGP and of hamster oviduct-specific glycoprotein (oviductin) , it was inferred that the derived amino acid sequence contained a sig nal peptide region of 21 amino acids and a mature MOGP (core protein) region of 700 amino acids (76 515 daltons). It was also inferred that the mature MOGP contained three potential N-linked glycosylation sites and 24 possible O-linked glycosylation sites, and had the unique seve n-residue repeat sequence (21 repeats) within the predicted sequence i n the C-terminal side, The amino acid sequence of a portion of MOGP wa s highly homologous to that of BOGP (71% identity), baboon oviduct-spe cific glycoprotein (61% identity), and human oviduct-specific glycopro tein 177% (dentity), Significant homologies were also observed with tw o mammalian secretory proteins that were reported as a mammalian membe r of a chitinase protein family, Northern blot hybridization with a DI G-labeled probe indicated that a single message of 2.8 kb was present in total RNA prepared from oviductal tissue. in situ hybridization usi ng MOGP-cDNA showed that a MOGP message was only detected in the ovidu ctal epithelial cells. These results strongly suggest that a significa nt degree of homology exists among oviduct-specific glycoproteins of v arious mammalian species.