Biology subjects

Lagoutte, P.

Publications and source records attributed to Lagoutte, P..

3 recordsLinked to original sources

bioRxiv2026

A recombinant heterotrimeric mini-procollagen I reveals new functional and structural roles for the α2(I) chain

Collagen I provides mechanical stability to organs and plays a critical role in several physiological processes such as wound healing and bone remodeling. Its ability to form fibrils depends on the proteolytic conversion of soluble procollagen I into mature protomers. However, the mechanistic aspects of this critical step have been difficult to analyze due to the lack of recombinant procollagen I suitable for structural and biochemical analyses. Here, we describe the successful production and purification of a heterotrimeric mini-procollagen I [1(I)22(I)] together with its homotrimeric counterpart [1(I)3] in HEK293-F cells. These tools were used to probe the specific role of the 2(I) chain both in procollagen I assembly and proteolytic maturation. While the presence of 2(I) in the heterotrimer does not strengthen trimer interfaces on its own, as revealed by cryo-electron microscopy, it provides a clear functional advantage to the procollagen substrate that is cleaved more efficiently by bone morphogenetic protein 1 (BMP-1) than the homotrimer. Furthermore, we demonstrate that the first cleavage event in the heterotrimer is at the level of the 2(I) chain, through a mechanism involving its C-telopeptide and a specific PRS motif close to the cleavage site. The preferential cleavage of 2(I) by BMP-1 can be partially corrected in the presence of PCPE-1 (procollagen C-proteinase enhancer 1) but the efficacy of the correction depends on its position on the procollagen trimer. Finally, we solved the high-resolution structure of the complex between the heterotrimer and PCPE-1 and proposed a new mechanism to explain the enhancing activity of PCPE-1.

biochemistry↗

bioRxiv2026

Structure of PCPE-2 in complex with the BMP-1 metalloprotease reveals the molecular basis of its mechanism of inhibition

PCPE-2 (procollagen C-proteinase enhancer-2) is an extracellular glycoprotein playing dual functions in the regulation of BMP-1/tolloid-like proteinases. Like its homologue PCPE-1, PCPE-2 can enhance the proteolytic maturation of fibrillar procollagens, but it also acts as a potent and specific inhibitor of BMP-1 through formation of a high-affinity complex with the protease. Here, we investigated the molecular basis of this inhibitory interaction using complementary biochemical, biophysical and structural approaches. We show that the two CUB domains of PCPE-2 must be covalently linked for efficient BMP-1 binding and inhibition, consistent with cooperative engagement of the protease. Cryo-electron microscopy combined with density-guided structural modelling and hydrogen/deuterium-exchange mass spectrometry supports a bipartite interaction complex in which the CUB1 domain of PCPE-2 engages the catalytic domain of BMP-1, while the CUB2 domains of both proteins interact together. The interaction involves the calcium-binding surfaces of the PCPE-2 CUB domains that also participate in procollagen recognition, providing a structural framework for understanding the mutually exclusive interactions of PCPE-2 with BMP-1 and procollagen. Allosteric inhibition is supported by the binding of PCPE-2 CUB1 opposite to the active site cleft, leading to the shielding of the residues surrounding the S1-prime pocket, as observed by HDX-MS. Together, these findings define the architecture of the inhibitory PCPE-2/BMP-1 complex and provide the molecular basis for understanding the distinct regulatory activities of the two procollagen C-proteinase enhancers.

biochemistry↗

bioRxiv2021

Procollagen C-Proteinase Enhancer 1 (PCPE-1) is a marker of myocardial fibrosis and impaired cardiac function in a murine model of pressure overload

(1) AimsProcollagen C-proteinase enhancer 1 (PCPE-1) is an extracellular matrix protein and a major regulator of fibrillar collagen biosynthesis. Previous work has shown that its abundance is often increased in the context of tissue repair and fibrosis. The present study was designed to evaluate its potential as a biomarker of myocardial interstitial fibrosis (MIF), a well-established pathogenic pathway leading to heart failure. (2) Methods and ResultsCardiac fibrosis was induced in rats using an optimized model of chronic pressure overload triggered by angiotensin II and N{omega}-nitro-L-arginine methyl ester (L-NAME). All treated animals suffered from heart hypertrophy and the increase in heart collagen volume fraction (CVF), evidenced by histology and 68Ga-Collagelin uptake, confirmed the development of cardiac fibrosis. Functional analysis by simultaneous PET-MRI further showed that our model closely reflected the pathological features seen in human MIF, including left ventricle thickening and diastolic dysfunction associated with decreased ejection fraction. PCPE-1 mRNA and protein levels were augmented by factors of 3.4 and 6.1 respectively in the heart tissue of treated rats. Moreover, protein abundance was well-correlated with CVF (r=0.92, p<0.0001) and PCPE-1 immuno-detection mainly localized the protein to fibrotic areas. Finally, PCPE-1 plasma levels measured by ELISA were increased in fibrotic rats compared to controls. (3) ConclusionTogether, our findings demonstrate that PCPE-1 levels in the heart and circulation tightly reflect the cardiac fibrosis status and heart function impairment in rats and suggest that it could be a very useful marker to monitor human heart diseases leading to fibrosis.

physiology↗