ArticleProceedings of the National Academy of Sciences of the United States of America2013
Expression of recombinant human complement C1q allows identification of the C1r/C1s-binding sites.
Article in Proceedings of the National Academy of Sciences of the United States of America, 2013. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 38 papers.
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Who cites it
38 citing papers in PubMed, 58 citations in OpenAlex.
- Article
- Serum C1q as a Novel Predictive Biomarker for Postoperative Delirium After Acute Type A Aortic Dissection.Immunity, inflammation and disease · 2026Article
- Engineering Liposomes and Polymer Conjugates: A Platform for Mechanistic Complement Activation Studies and Controlled Release Applications.ACS applied materials & interfaces · 2026Article
- Young adult microglial deletion of C1q reduces engulfment of synapses and prevents cognitive impairment in an aggressive Alzheimer's disease mouse model.bioRxiv : the preprint server for biology · 2025Article
- A Collagen Triple Helix without the Superhelical Twist.ACS central science · 2025Article
- A Collagen Triple Helix without the Super Helical Twist.bioRxiv : the preprint server for biology · 2024Article
- Structural basis for surface activation of the classical complement cascade by the short pentraxin C-reactive protein.Proceedings of the National Academy of Sciences of the United States of America · 2024Article
- Correlated evolution of social organization and lifespan in mammals.Nature communications · 2023Article
- LAIR-1 acts as an immune checkpoint on activated ILC2s and regulates the induction of airway hyperreactivity.The Journal of allergy and clinical immunology · 2022Article
- Complement System and Alarmin HMGB1 Crosstalk: For Better or Worse.Frontiers in immunology · 2022Review
- Molecular Basis of Complement C1q Collagen-Like Region Interaction with the Immunoglobulin-Like Receptor LAIR-1.International journal of molecular sciences · 2021Article
- Epitope-Specific Anti-C1q Autoantibodies in Systemic Lupus Erythematosus.Frontiers in immunology · 2021Article
- The endogenous neuronal complement inhibitor SRPX2 protects against complement-mediated synapse elimination during development.Nature neuroscience · 2020Article
- Identification of Neuronal Pentraxins as Synaptic Binding Partners of C1q and the Involvement of NP1 in Synaptic Pruning in Adult Mice.Frontiers in immunology · 2020Article
- Complement C1q Interacts With LRP1 Clusters II and IV Through a Site Close but Different From the Binding Site of Its C1r and C1s-Associated Proteases.Frontiers in immunology · 2020Article
- Recombinant C1q variants modulate macrophage responses but do not activate the classical complement pathway.Molecular immunology · 2020Article
- Insights into IgM-mediated complement activation based on in situ structures of IgM-C1-C4b.Proceedings of the National Academy of Sciences of the United States of America · 2019Article
- The Multiple Faces of C-Reactive Protein-Physiological and Pathophysiological Implications in Cardiovascular Disease.Molecules (Basel, Switzerland) · 2019Review
- Interaction of C1q With Pentraxin 3 and IgM Revisited: Mutational Studies With Recombinant C1q Variants.Frontiers in immunology · 2019Article
- C1q and Mannose-Binding Lectin Interact with CR1 in the Same Region on CCP24-25 Modules.Frontiers in immunology · 2018Article
Corrections and comments
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Authors and funding
9 authors at 5 institutions in 2 countries.
Funding
No grant is acknowledged in the PubMed record.
Abstract
Complement C1q is a hexameric molecule assembled from 18 polypeptide chains of three different types encoded by three genes. This versatile recognition protein senses a wide variety of immune and nonimmune ligands, including pathogens and altered self components, and triggers the classical complement pathway through activation of its associated proteases C1r and C1s. We report a method for expression of recombinant full-length human C1q involving stable transfection of HEK 293-F mammalian cells and fusion of an affinity tag to the C-terminal end of the C chain. The resulting recombinant (r) C1q molecule is similar to serum C1q as judged from biochemical and structural analyses and exhibits the characteristic shape of a bunch of flowers. Analysis of its interaction properties by surface plasmon resonance shows that rC1q retains the ability of serum C1q to associate with the C1s-C1r-C1r-C1s tetramer, to recognize physiological C1q ligands such as IgG and pentraxin 3, and to trigger C1r and C1s activation. Functional analysis of rC1q variants carrying mutations of LysA59, LysB61, and/or LysC58, in the collagen-like stems, demonstrates that LysB61 and LysC58 each play a key role in the interaction with C1s-C1r-C1r-C1s, with LysA59 being involved to a lesser degree. We propose that LysB61 and LysC58 both form salt bridges with outer acidic Ca(2+) ligands of the C1r and C1s CUB (complement C1r/C1s, Uegf, bone morphogenetic protein) domains. The expression method reported here opens the way for deciphering the molecular basis of the unusual binding versatility of C1q by mapping the residues involved in the sensing of its targets and the binding of its receptors.
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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.