Turnover of glial filaments in mouse spinal cord.
Twenty-day-old mice received a single tail vein injection of [guanido-14C]arginine. The cytoskeleton was extracted from the spinal cords at varying lengths of time thereafter. Glial fibrillary acidic protein (GFAP) formed a distinct, broad band that was widely separated from other protein bands in one-dimensional polyacrylamide gels. The purity of the GFAP band was verified by Western blot analysis of one- and two-dimensional electrophoretic patterns. In addition, enzyme-linked immunosorbent assay and quantitative Western blot analysis indicated that 95% of the total spinal cord GFAP was extracted in the cytoskeletal preparation. The specific activity of GFAP was obtained by eluting the protein from the cytoskeletal GFAP band in preparative one-dimensional gels. Specific activity reached a peak 2 h after injection with [14C]arginine. Forty percent of the incorporated radioactivity was still present in cytoskeletal GFAP at 9 weeks, indicating that a significant proportion of glial filaments turns over relatively slowly in vivo.
D000818:Animals; D001253:Astrocytes / Q000378:metabolism; D003599:Cytoskeleton / Q000378:metabolism*; D004591:Electrophoresis, Polyacrylamide Gel; D005260:Female; D005904:Glial Fibrillary Acidic Protein / Q000378:metabolism*; D007124:Immunoenzyme Techniques; D007382:Intermediate Filaments / Q000378:metabolism*; D008297:Male; D051379:Mice; D008816:Mice, Jimpy; D013116:Spinal Cord / Q000378:metabolism*
D005904:Glial Fibrillary Acidic Protein