|
Complement receptor type 2 (CR2), also known as complement C3d receptor, Epstein-Barr virus receptor, and CD21 (cluster of differentiation 21), is a protein that in humans is encoded by the CR2 gene. CR2 is involved in the complement system. It binds to iC3b (inactive derivative of C3b), C3dg, or C3d.〔Frank K, Atkinson JP (2001). "Complement system." In Austen KF, Frank K, Atkinson JP, Cantor H. eds. ''Samter's Immunologic Diseases, 6th ed. Vol. 1,'' p. 281-298, Philadelphia: Lippincott Williams & Wilkins, ISBN 0-7817-2120-2.〕 B cells have CR2 receptors on their surfaces, allowing the complement system to play a role in B-cell activation and maturation 〔(【引用サイトリンク】 url = http://www.ncbi.nlm.nih.gov/sites/entrez?Db=gene&Cmd=ShowDetailView&TermToSearch=1380 )〕 ==Interactions== CR2 on mature B cells form a complex with two other membrane proteins, CD19 and CD81(=TAPA-1). The CR2-CD19-CD81 complex is often called the B cell coreceptor complex,〔Abbas AK, Lichtman AH (2003). ''Cellular and Molecular Immunology, 5th ed.'' Philadelphia: Saunders, ISBN 0-7216-0008-5〕 because CR2 binds to antigens through attached C3d (or iC3b or C3dg) when the membrane IgM binds to the antigen. This results in the B cell having greatly enhanced response to the antigen.〔 Complement receptor 2 has been shown to interact with CD19. Epstein-Barr virus (EBV) binds to B cells at CR2 during infection of these cells. Yefenof et al. (1976) found complete overlapping of EBV receptors and C3 receptors on human B cells.〔 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Complement receptor 2」の詳細全文を読む スポンサード リンク
|