Classical Complement Pathway

Preferred Label : Classical Complement Pathway;

Alternative definition : BIOCARTA: The complement system is part of the defense against invading cells and is composed of about twenty different proteins found in the plasma. When activated, complement proteins form a pathway of proteolytic reactions that culminates in the lysis of foreign cells. The complement system also stimulates phagocytosis of foreign cells and an inflammatory response. There are two different complement systems, the classical complement pathway initiated by antibody complexes on the cell surface, and an alternative complement pathway that is initiated without antibodies. The complement system proteins are named with a capital C followed by a number. A small letter after the number indicates that the protein is a smaller protein resulting from the cleavage of a larger precursor by a protease. In the classical pathway, the first step is the initiation of the pathway triggered by recognition by complement factor C1 of antigen-antibody complexes on the cell surface. When C1 complex interacts with aggregates of IgG with antigen on a cell's surface, two C1-associated proteases, C1r and C1s, are activated. Other factors like lipopolysaccharide also activate C1s. Once C1s is activated, it cleaves C4 to form C4b that then binds to the cell membrane of the cell being attacked. The proteolytic complement cascade is then amplified on the cell membrane through sequential cleavage of complement factors and recruitment of new factors until a cell surface complex containing C5b, C6, C7, and C8 is formed. The addition of a multiple C9 proteins creates the membrane attack complex results in a large pore that spans the membrane of the cell being attacked, allowing ions to flow freely between the cellular interior and exterior. Ions flow out, but large molecules stay in, causing water to flood into the cell and ultimately burst the cell from osmotic pressure. (This definition may be outdated - see the DesignNote.);

NCIt note : The BIOCARTA Definition (ALT_DEFINITION) for this pathway concept was provided by BioCarta. This property was not created by, nor is it maintained by the NCI Thesaurus staff. Additionally, BioCarta is no longer updating its pathway data; thus, the BIOCARTA Definition might be outdated or inaccurate. Please see the Terms and Conditions for Use at http://www.biocarta.com/.;

Biocarta ID : h_classicPathway;

Details

Origin ID

C39032;

UMLS CUI

C0009547;

Automatic exact mappings (from CISMeF team)
- Complement activation classic pathway, function (observable entity) [SNOMED CT concept]
- complement activation classic pathway, nos [SNOMED Notion]
Currated CISMeF NLP mapping
- complement pathway, classical [MeSH Descriptor]
- complement pathway, classical [MeSH concept]
Semantic type(s)
- Molecular Function [UMLS semantic type]
UMLS correspondences (same concept)
- complement pathway, classical [MeSH concept]
- complement pathway, classical [MeSH Descriptor]
has_gene_product_element
- C3a Anaphylatoxin [NCIt concept]
- Clusterin [NCIt concept]
- Complement C1q Subcomponent Subunit A [NCIt concept]
- Complement C1q Subcomponent Subunit B [NCIt concept]
- Complement C1q Subcomponent Subunit C [NCIt concept]
- Complement C1r Subcomponent [NCIt concept]
- Complement C1s Subcomponent [NCIt concept]
- Complement C2 [NCIt concept]
- Complement C3 [NCIt concept]
- Complement C3 Beta Chain [NCIt concept]
- Complement C3d [NCIt concept]
- Complement C4-A [NCIt concept]
- Complement C4-B [NCIt concept]
- Complement C5 [NCIt concept]
- Complement Receptor Type 1 [NCIt concept]
pathway_has_gene_element
- C1QA wt Allele [NCIt concept]
- C1QB wt Allele [NCIt concept]
- C1QC wt Allele [NCIt concept]
- C1R wt Allele [NCIt concept]
- C1S wt Allele [NCIt concept]
- C2 wt Allele [NCIt concept]
- C3 wt Allele [NCIt concept]
- C4A wt Allele [NCIt concept]
- C4B wt Allele [NCIt concept]
- C5 wt Allele [NCIt concept]
- CLU wt Allele [NCIt concept]

Keyword's position in hierarchy(ies) :

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