ADAMTS proteins (disintegrins and metalloproteinases with thrombospondin motifs) have been associated with various biological processes including follicular development and ovulation. Some members are considered orphan proteins because their specific substrates have not been described (e.g. ADAMTS19). Specifically ADAMTS19 has recently been suggested as a candidate gene for FOP. In the present study a screening of the potential interaction proteins (partners) of ADAMTS19 was carried out using yeast two hybrid assay. Co-immunoprecipitation was performed on transfected cells and human follicular fluid to verify the direct interaction between ADAMTS19 and COL6A2. RT-PCR assays werw performed to evaluate co-expression of Adamts19 and Col6a2 in mouse ovaries. In addition, the indirect immunofluorescence technique used to evaluate the colocalization of proteins. It was found that ADAMTS19 binds directly to COL6A2 in an ovarian context which correlates with the findings of coexpression and colocalization in human follicular fluid. We propose that ADAMTS19 acts on the microfibers of COL6A2 during follicular growth and expansion of the basal lamina. We found that the p.Thr943Ile ADAMTS19 mutation previously identified in a patient with FOP did not alter the ADAMTS19 / COL6A2 interaction. However, we do not rule out that the mutation contributes to the FOP phenotype. The results of this work, which describe the first direct interaction protein of ADAMTS19, yield new data on the role of metalloproteinases in ovarian biology and fertility.
