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Updated: Aug 4, 2025
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Imaging Denatured Collagen Strands In vivo and Ex vivo via Photo-triggered Hybridization of Caged Collagen Mimetic Peptides
Published on: January 31, 2014
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Tissue-specific collagen hydroxylation at GEP/GDP triplets mediated by P4HA2
Dafné Wilhelm1, Alison Wurtz1, Hanane Abouelfarah1
1Université de Lorraine, CNRS, IMoPA, UMR 7365, Nancy F-54000, France.
Summary
Tissue-specific collagen hydroxylation is regulated by Prolyl-4-hydroxylase 2 (P4HA2). Lower P4HA2 expression in tendons impacts collagen structure and mechanical properties, a finding conserved across species.
Area of Science:
- Biochemistry
- Molecular Biology
- Connective Tissue Research
Background:
- Collagen, a vital structural protein, requires extensive post-translational modification, including prolyl-4-hydroxylation (P4H), for tissue mechanical properties.
- Prolyl-4-hydroxylases (P4HA1-3) catalyze P4H, crucial for collagen's triple helix stability.
- Previous research lacked evidence for tissue-specific regulation of P4H or differential substrate specificity among P4HAs.
Purpose of the Study:
- To investigate tissue-specific regulation of collagen post-translational modifications, specifically P4H patterns.
- To identify the role of different Prolyl-4-hydroxylase alpha subunits (P4HA1-3) in tissue-specific collagen assembly.
- To explore the functional significance of P4HA2 in tendon collagen modification.
Main Methods:
- Comparative analysis of collagen post-translational modifications in bone, skin, and tendon from mouse and chicken.
- Mass spectrometry to identify and quantify hydroxylation patterns on collagen alpha chains.
- Genetic invalidation of P4ha2 in the ATDC5 cellular model to assess its impact on collagen assembly.
Main Results:
- Tendon collagen exhibited significantly lower hydroxylation at GEP/GDP triplets and other residue positions compared to bone and skin.
- This distinct hydroxylation pattern was conserved in both mouse and chicken, suggesting evolutionary regulation.
- Low P4ha2 expression in tendon and its invalidation in ATDC5 cells mimicked the tendon-specific P4H profile, indicating P4HA2's specific role.
Conclusions:
- Prolyl-4-hydroxylase 2 (P4HA2) plays a key role in the tissue-specific hydroxylation of collagen.
- Local P4HA2 expression levels are a critical determinant of collagen's P4H profile and, consequently, connective tissue properties.
- This study reveals a novel mechanism of tissue specificity in collagen assembly mediated by P4HA2.
Keywords:
4-hydroxyprolineBoneMass spectrometryProlyl-4-hydroxylaseRelative quantificationSkinTendonType I collagenMore Related Videos
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