Engelsk definition
Membrane proteins in precursor B-LYMPHOCYTES (pre-B Cells). They are composed of membrane-bound MU IMMUNOGLOBULIN HEAVY CHAINS in complex with SURROGATE LIGHT CHAINS instead of conventional IMMUNOGLOBULIN LIGHT CHAINS. Only successful rearrangement of the VDJ segments, at the Ig heavy chain gene locus (IMMUNOGLOBULIN HEAVY CHAIN GENES), will generate mu heavy chains that can pair with surrogate light chains. Thus formation of the pre-B cell receptors is an important checkpoint in the development of mature B cells.