Identification of binding partners interacting with the α1-N-propeptide of type V collagen

Sofie Symoens , Marjolijn Renard , Christelle Bonod Bidaud , Delfien Syx , Elisabeth Vaganay , Fransiska Malfait , Sylvie Ricard-Blum , Efrat Kessler , Lut van Laer , Paul Coucke , Florence Ruggiero , Anne de Paepe (1)

1 Center for Medical Genetics

The predominant form of type V collagen is the [α1(V)]2α2(V) heterotrimer. Mutations in COL5A1 or COL5A2, encoding respectively the α1(V)- and α2(V)-collagen chain, cause classic Ehlers-Danlos syndrome (EDS), a heritable connective tissue disorder, characterized by fragile hyperextensible skin and joint hypermobility. Approximately half of the classic EDS cases remains unexplained. Type V collagen controls collagen fibrillogenesis through its conserved α1(V)-amino(N)-propeptide domain. To gain insight into the role of this domain, a yeast-two-hybrid screen among proteins expressed in human dermal fibroblasts was performed utilizing the amino(N)-propeptide as a bait. We identified 12 interacting proteins including extracellular matrix proteins and proteins involved in collagen biosynthesis. Eleven interactions were confirmed by surface plasmon resonance and/or co-immunoprecipitation: α1(I)- and α2(I)-collagen chains, α1(VI)-, α2(VI)- and α3(VI)-collagen chains, tenascin-C, fibronectin, procollagen C-proteinase enhancer-1 (PCPE-1), tissue inhibitor of metalloproteinases-1, matrix metalloproteinase-2 and transforming growth factor-β1. Solid-phase binding assays confirmed the involvement of the α1(V)-N-propeptide in the interaction between native type V collagen and type VI collagen, suggesting a bridging function of this protein complex in the cell-matrix environment. Enzymatic studies showed that processing of the α1(V)-N-propeptide by the procollagen C-proteinase BMP-1 is enhanced by PCPE-1. These interactions are likely involved in ECM homeostasis and their disruption could explain the pathogenetic mechanism in unresolved classic EDS cases.

Mots clés: Life Sciences

Sofie Symoens, Marjolijn Renard, Christelle Bonod Bidaud, Delfien Syx, Elisabeth Vaganay, et al.. Identification of binding partners interacting with the α1-N-propeptide of type V collagen. Biochemical Journal, 2010, 433 (2), pp.371-381. ⟨10.1042/BJ20101061⟩. ⟨hal-00549896⟩