The dispensability of V-V pairing and the indispensability of V domain integrity in the IgG1 secretion process.

The C domain of IgG antibodies controls assembly and secretion, mediated by the molecular chaperone BiP via the endoplasmic reticulum protein quality control (ERQC) mechanism. However, it is not clear whether the variable domains are necessary for this process. Here, we generated IgG1 antibodies in which the V domain (V and/or V) was either removed or replaced, and then assessed expression, assembly, and secretion in HEK293 cells.