Carboxypeptidase that, together with KPI106, controls mycorrhiza establishment and arbuscule development during root colonization by arbuscular mycorrhizal (AM) fungi (e.g. Rhizophagus irregularis). Interacts with KPI106 and KPI111. Accumulates in roots, in a RAM1-dependent manner, during colonization by arbuscular mycorrhizal (AM) fungi (e.g. Glomus versiforme). Aberrant mycorrhizal development with an increased number of septated hyphae and degenerate arbuscules during root colonization by arbuscular mycorrhizal (AM) fungi (e.g. Rhizophagus irregularis). Belongs to the peptidase S10 family.