CD21; complement receptor type 2; Cr2; complement C3d receptor; Epstein-Barr virus receptor; EBV receptor (CR2, C3DR)

Function

• receptor for complement C3Dd
• receptor for HNRPU
• participates in B lymphocytes activation
• forms complex with CD19, CD81 & CD225

Structure

• belongs to the receptors of complement activation (RCA) family
• contains 15 Sushi domains (CCP/SCR)

Compartment

membrane

Alternative splicing

named isoforms=4

Expression

• mature B-cells; CD21 is present on resting B-cells
• follicular dendritic cells
• T-lymphocytes
• pharyngeal epithelial cells
• astrocytes

Pathology

• receptor for Epstein-Barr virus on human B-cells & T-cells
• genetic variations in CR2 are associated with susceptibility to systemic lupus erythematosus type 9

Laboratory

• CD21 & CD23 are dendritic cell markers

More general terms

• CD antigen
• complement receptor

Additional terms

• complement C3d
• Epstein-Barr virus (EBV); human herpesvirus 4 (HHV4)

Database

• Kegg: http://www.genome.jp/dbget-bin/www_bget?hsa:1380
• OMIM: https://mirror.omim.org/entry/120650
• OMIM: https://mirror.omim.org/entry/610927
• UniProt: http://www.uniprot.org/uniprot/P20023.html