C1QA

C1QA, Complement C1q Subcomponent A, is a protein that plays a key role in the human immune system.C1QA is one of the components of the C1 complex of the serum complement system and binds to two precursor enzymes, C1r and C1s, to form C1.C1QA consists of six identical polypeptide chains that interact with the precursor enzyme complexes of C1r and C1s through their collagen-like regions and bind to the Fc region of the immune complex through their spherical heads to trigger the C1 cascade. C1r and C1s precursor enzyme complexes, and through its spherical head binds to the Fc region of immune complexes, triggering a complement cascade reaction.

C1QA is critical in host defence mechanisms, participating in the recognition and clearance of immune complexes, promoting phagocytosis, regulating cytokine production, and influencing T-lymphocyte maturation. In addition, C1QA is involved in tissue repair, tumour immunosurveillance, and homeostatic regulation of the central nervous system.The function of C1QA is important for the maintenance of immune homeostasis and the prevention of autoimmune diseases, and its roles in a variety of physiological and pathological processes suggest a complex role in immune regulation and cellular processes.