C4 Recombinant Rabbit Monoclonal Antibody [JM88-13] (ET1705-10)

UNIPROT #

P0C0L4

PROTEIN NAME

C4

SYNONYMS

Acidic C4 antibody;Acidic complement C4 antibody;Basic C4 antibody;Basic complement C4 antibody;C3 and PZP-like alpha-2-macroglobulin domain-containing protein 2 antibody;C3 and PZP-like alpha-2-macroglobulin domain-containing protein 3 antibody;C4, Chido form antibody;C4, Rodgers from antibody;C4A anaphylatoxin antibody;C4A antibody;C4A2 antibody;C4A3 antibody;C4A4 antibody;C4A6 antibody;C4AD antibody;C4B antibody;C4B_2 antibody;C4B1 antibody;C4B12 antibody;C4B2 antibody;C4B3 antibody;C4BD antibody;C4F antibody;C4S antibody;CH antibody;Chido form of C4 antibody;CO4 antibody;CO4A_HUMAN antibody;Complement C4 gamma chain antibody;complement C4-A antibody;complement C4-B antibody;complement C4-B-like antibody;complement C4B1a antibody;Complement component 4A (Rodgers blood group) antibody;Complement component 4A antibody;complement component 4B (Chido blood group), copy 2 antibody;Complement component 4B (Childo blood group) antibody;Complement component 4B antibody;Complement component 4F antibody;Complement component 4S antibody;CPAMD2 antibody;CPAMD3 antibody;RG antibody;Rodgers form of C4 antibody

TISSUE SPECIFICITY

Complement component C4 is expressed at highest levels in the liver, at moderate levels in the adrenal cortex, adrenal medulla, thyroid gland, and the kidney, and at lowest levels in the heart, ovary, small intestine, thymus, pancreas and spleen. The extra-hepatic sites of expression may be important for the local protection and inflammatory response.

POST-TRANSLATIONAL MODIFICATION

Prior to secretion, the single-chain precursor is enzymatically cleaved to yield non-identical chains alpha, beta and gamma. During activation, the alpha chain is cleaved by C1 into C4a and C4b, and C4b stays linked to the beta and gamma chains. Further degradation of C4b by C1 into the inactive fragments C4c and C4d blocks the generation of C3 convertase. The proteolytic cleavages often are incomplete so that many structural forms can be found in plasma.; N- and O-glycosylated. O-glycosylated with a core 1 or possibly core 8 glycan.

SUBCELLULAR LOCATION

Cell junction, Cell projection, Secreted, Synapse.

FUNCTION

Complement component 4 (C4), in humans, is a protein involved in the intricate complement system, originating from the human leukocyte antigen (HLA) system. It serves a number of critical functions in immunity, tolerance, and autoimmunity with the other numerous components. Furthermore, it is a crucial factor in connecting the recognition pathways of the overall system instigated by antibody-antigen (Ab-Ag) complexes to the other effector proteins of the innate immune response. For example, the severity of a dysfunctional complement system can lead to fatal diseases and infections. Complex variations of it can also lead to schizophrenia. Yet, the C4 protein derives from a simple two-locus allelic model, the C4A-C4B genes, that allows for an abundant variation in the levels of their respective proteins within a population. Originally defined in the context of the Chido/Rodgers blood group system, the C4A-C4B genetic model is under investigation for its possible role in schizophrenia risk and development.