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

Abstract

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 EDS (Ehlers-Danlos syndrome), a heritable connective tissue disorder, characterized by fragile hyperextensible skin and joint hypermobility. Approximately half of the classic EDS cases remain unexplained. Type V collagen controls collagen fibrillogenesis through its conserved α1(V)-N-propeptide domain. To gain an insight into the role of this domain, a yeast two-hybrid screen among proteins expressed in human dermal fibroblasts was performed utilizing the 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, PCPE-1 (procollagen C-proteinase enhancer-1), TIMP-1 (tissue inhibitor of metalloproteinases-1), MMP-2 (matrix metalloproteinase 2) and TGF-β1 (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 BMP-1 (bone morphogenetic protein 1)/procollagen C-proteinase is enhanced by PCPE-1. These interactions are likely to be involved in extracellular matrix homoeostasis and their disruption could explain the pathogenetic mechanism in unresolved classic EDS cases.

Large-Scale Investigation of Leishmania Interaction Networks with Host Extracellular Matrix by Surface Plasmon Resonance Imaging

“…In order to identify the partners of Leishmania on a large scale, we performed binding assays with intact live Leishmania promastigotes by using protein and glycosaminoglycan arrays previously developed in our laboratory (12)(13)(14). We investigated the ability of the logarithmic-phase promastigotes of 24 Leishmania strains and of the stationary-phase promastigotes of three of these strains to interact with ϳ70 molecules present in the skin, basement membrane, and blood vessels of their mammalian hosts.…”

Regulation of Collagen Fibril Nucleation and Initial Fibril Assembly Involves Coordinate Interactions with Collagens V and XI in Developing Tendon

“…with fibronectin interactions. This possibility is supported by a recent analysis indicating that the NH 2 non-collagenous domain of collagen V interacts with numerous matrix proteins that could generate such interactions (62). Alterations in collagens V and XI would compromise control of initial protofibril assembly and deposition by freeing the process from its normal regulatory domain.…”

Membrane-Associated Matrix Proteolysis and Heart Failure

“…The myocardial ECM was historically considered to be a relatively static structure composed of fibrillar collagens with relatively slow turnover rates, but it is now apparent that the ECM is a complex and dynamic entity. All of these ECM constituents are vulnerable to proteolytic processing directly or indirectly by MMPs, 65–69 which in turn will alter the interactions between these different structural and biologically active interstitial molecules, and thereby determine the overall structure and function of the ECM. Changes in the structure and function of the ECM hold physiological implications in terms of both LV systolic and diastolic performances.…”