title: Breast cancer-associated mutations in metalloprotease disintegrin ADAM12 interfere with the intracellular trafficking and processing of the protein.
abstract: ADAM12 has recently emerged as a Candidate Cancer Gene in a comprehensive genetic analysis of human breast cancers. Three somatic mutations in ADAM12 were observed at significant frequencies in breast cancers: D301H, G479E and L792F. The first 2 of these mutations involve highly conserved residues in ADAM12, and our computational sequence analysis confirms that they may be cancer-related. We show that the corresponding mutations in mouse ADAM12 inhibit the proteolytic processing and activation of ADAM12 in NIH3T3, COS-7, CHO-K1 cells and in MCF-7 breast cancer cells. The D/H and G/E ADAM12 mutants exert a dominant-negative effect on the processing of the wild-type ADAM12. Immunofluorescence analysis and cell surface biotinylation experiments demonstrate that the D/H and G/E mutants are retained inside the cell and are not transported to the cell surface. Consequently, the D/H and G/E mutants, unlike the wild-type ADAM12, are not capable of shedding Delta-like l, a ligand for Notch receptor, at the cell surface, or of stimulating cell migration. Our results suggest that the breast cancer-associated mutations interfere with the intracellular trafficking of ADAM12 and result in loss of the functional ADAM12 at the cell surface.
authors.affiliation: Department of Biochemistry, Kansas State University, Manhattan, KS 66506, USA.
authors.forename: Emilia
authors.initials: E
authors.lastname: Dyczynska
authors.forename: Emilia
authors.initials: E
authors.lastname: Syta
authors.forename: Danqiong
authors.initials: D
authors.lastname: Sun
authors.forename: Anna
authors.initials: A
authors.lastname: Zolkiewska
mesh_terms: D051722:ADAM Proteins / Q000235:genetics* / Q000378:metabolism*; D000072199:ADAM12 Protein; D000818:Animals; D001224:Aspartic Acid; D019921:Biotinylation; D015153:Blotting, Western; D001943:Breast Neoplasms / Q000235:genetics* / Q000378:metabolism*; D002465:Cell Movement; D005260:Female; D005455:Fluorescent Antibody Technique; D018698:Glutamic Acid; D005998:Glycine; D006639:Histidine; D006801:Humans; D047468:Immunoprecipitation; D007930:Leucine; D008565:Membrane Proteins / Q000235:genetics* / Q000378:metabolism*; D051379:Mice; D009154:Mutation; D010649:Phenylalanine
chemical_list: D008565:Membrane Proteins; D001224:Aspartic Acid; D018698:Glutamic Acid; D010649:Phenylalanine; D006639:Histidine; D051722:ADAM Proteins; D000072199:ADAM12 Protein; C000606480:ADAM12 protein, human; C096115:Adam12 protein, mouse; D007930:Leucine; D005998:Glycine