|MoBio||Immunoglobulin Family||Chapter 2|
This protein family transmit signals for immune responses. Each of them contains one or two transmembrane segments. The immunoglobulin (i.e., antibody) consists of four peptide chains: two heavy chains and two light chains. VH and CH represent the variable and conserved domains of the heavy chain, respectively; VL and CL denote those for the light chain. Variable domains are the binding site of antigens. To send signals into the cell, this class of proteins are typically coupled to non-receptor protein tyrosine kinase located on the cytosolic face of the plasma membrane.