Analysis and Comparison of In Vitro Synthesized Glial Fibrillary Acidic Protein with Rat CNS Intermediate Filament Proteins

Abstract

Intermediate filament (IF) proteins from rat spinal cord were analyzed by 2-dimensional gel electrophoresis and compared with the in vitro translation products of a mRNA-dependent reticulocyte lysate system stimulated with 16 day old rat brain polysomes. In 2 dimensions, the MW 49,000-50,000 band of the IF preparation resolved to 7 spots, whereas antiserum to glial fibrillary acidic (GFA) protein precipitated 2 immediately adjacent radiolabeled in vitro synthesized products, with MW of 49,000-50,000. Autoradiographs of 2-dimensional gels of extracted IF proteins incubated with iodinated IgG fraction of GFA protein antiserum showed that all 7 spots were recognized by the antiserum. The primary gene product of GFA protein is modified either by post-translational processing or experimental artifact.