Background
This gene encodes complement protein C3 which plays a central role in the classical,
alternative and lectin activation pathways of the complement system. The encoded
preproprotein undergoes a multi-step processing to generate various functional peptides.
Mice deficient in the encoded protein fail to clear bacteria from the blood stream upon
infection, display diminished airway hyperresponsiveness and lung eosinophilia upon
allergen-induced pulmonary allergy, and develop severe lung injury after deposition of IgG
immune complexes. Deficiency of the homolog of the encoded protein in humans was found
to be associated with increased susceptibility to infections, age-related macular
degeneration, and atypical hemolytic uremic syndrome.
