Complement C4 (P08649)

Uniprot ID P08649
Protein Name Complement C4
Gene Name C4
Species Rattus norvegicus (Rat)
Signal peptide(a) Y Secretome P(b)
Function Non-enzymatic component of C3 and C5 convertases and thus essential for the propagation of the classical complement pathway. Covalently binds to immunoglobulins and immune complexes and enhances the solubilization of immune aggregates and the clearance of IC through CR1 on erythrocytes (By similarity). .Derived from proteolytic degradation of complement C4, C4a anaphylatoxin is a mediator of local inflammatory processes. It induces the contraction of smooth muscle, increases vascular permeability and causes histamine release from mast cells and basophilic leukocytes.
GO - Molecular function
  • complement component C1q complex binding : ISO:RGD
  • endopeptidase inhibitor activity : IEA:InterPro
GO - Biological process
  • complement activation : ISO:RGD
  • complement activation, classical pathway : IEA:UniProtKB-KW
  • inflammatory response : IEA:UniProtKB-KW
  • innate immune response : IEA:UniProtKB-KW
  • positive regulation of apoptotic cell clearance : ISO:RGD
Back
(a) The Signal peptide D-score cutoff for "YES"(having signal peptide) is 0.45.
(b) Non-classically secreted proteins should obtain an NN-score(Neural Networks score) exceeding the normal threshold of 0.5, but not at the same time be predicted to contain a signal peptide.