Figure 4.

Schematic representation of the human CNMD gene (A) and its precursor protein (B). The gray boxes containing the letter ‘E’ in (A) represent one of the seven exons constituting the gene, divided by the introns represented by the letter ‘I’. Once translated, the precursor is a type II glycoprotein consisting of 334 amino acids (B), which begins from the N-terminal with a transmembrane region crossing from amino acid 45 to 65, followed by a BRICHOS domain ranging from amino acid 105 to 210, and an N-glycosylated site in amino acid 243 from which the mature form of CNMD originates. This domain is released by protease cleavage, namely the intracellular furin, using the RERR recognition site in position 215 of the amino acid sequence of the CNMD precursor. Abbreviations: bp (base pair); aa (amino acid).