Meprins are plasma membrane homo- or hetero-oligomeric metalloendopeptidases that contain glycosylated α and/or β subunits. This paper reports the cloning and sequencing of the mouse kidney β subunit. The primary translation product is composed of 704 amino acids which includes a transient signal sequence of 20 amino acids at the NH2 terminus. The protease domain (Asn-63 to Leu-260) contains the putative zinc-binding motif characteristic of metalloendopeptidases of the "astacin family." The COOH terminus contains an epidermal growth factor-like domain, a potential membrane-spanning domain, and an additional 26 amino acids. The β subunit has an overall 42% identity to the α subunit, however, a 56-amino acid segment near the COOH terminus of α is missing in β, and the putative transmembrane and cytoplasmic domains of the subunits share no significant sequence similarity. NH2-terminal analyses of detergent-solubilized mature forms revealed that, unlike α, the prosequence (Leu-21 to Lys-62) is not removed from the β subunit. Northern blot analysis revealed a 2.5-kilobase message for the β subunit in the kidney and intestine of C57BL/6 and C3H/He mice. The gene for the β subunit was localized to mouse chromosome 18. These studies indicate that α and β probably derived from a common ancestral gene, but have evolved so that their genes are on two different chromosomes, and their tissue-specific expression and post-translational processing differ.
|Original language||English (US)|
|Number of pages||9|
|Journal||Journal of Biological Chemistry|
|State||Published - 1993|
ASJC Scopus subject areas
- Molecular Biology
- Cell Biology