Intradermal DNA immunization: Antisera specific for the membrane lectin MR60/ERGIC-53

The trafficking of intracellular membrane proteins in Golgi apparatus, endo plasmic reticulum or intermediate compartment has not yet been fully elucid ated. The human MR60/ ERGIC-53 and the rat p58 proteins are one such protei n; and to study them in cell-free and in situ systems, high quality monospe cific antisera are required. Highly specific antisera have been obtained af ter immunization of mice with plasmids containing a gene encoding either th e full length or a truncated protein. The best results were obtained after intradermal injections of a plasmid encoding a truncated protein comprising both the luminal carbohydrate recognition domain and the stem down to a cy steine residue close to the C-terminal end, but neither the transmembrane n or the cytosolic domains. Such antisera have a very high titer and are very efficient tools to visualize the MR60 protein in situ or to selectively pr ecipitate the MR60 proteins from a whole cell lysate.