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C4d

Go to external page http://purl.obolibrary.org/obo/NCIT_C118185

C4d (380 aa, ~41 kDa) is a fragment of complement component-4. This protein plays a role in the regulation of the classical and lectin complement pathways. It may be a biomarker for complement activation during antibody-mediated rejection of transplants and in other pathological conditions. [ ]

Term info

Label

C4d

Synonyms
  • C4D
  • C4d
  • Complement C4d
  • Complement Component 4d
  • Complement Component-4d
Subsets

NCIT_C116977, NCIT_C142800, NCIT_C142799

DesignNote

Human complement component C4 is polymorphic at two loci, C4A and C4B, thus C4d is encoded by both of these genes. Both forms of complement component-4 can be cleaved to generate C4 alpha chain and C4 beta chain. The alpha chain can be further processed to release C4a anaphylatoxin and C4b. C4b is membrane bound and recruits C2a to form the C4b2a form of the C3-convertase in the classical complement pathway. To deactivate the C3-convertase, C4b is cleaved further to form the inactive fragments C4c and C4d. C4d remains bound to the surface of the endothelium.

Semantic Type

Amino Acid, Peptide, or Protein

UMLS CUI

C0056195

code

C118185