Phosphorylation protects neurofilaments against proteolysis.
During incubation with phosphatase, the 200 kDa neurofilament protein in cytoskeletal preparations is degraded extensively. Degradation, which is divalent cation-independent, does not occur when inhibitors of phosphatase are added. The 160 kDa chymotryptic fragment of neurofilaments or affinity-purified 200 kDa protein are not degraded by phosphatase. The results suggest that phosphorylated neurofilaments are protected against proteolysis, and dephosphorylated neurofilaments are degraded by a calcium-independent, endogenous proteinase which is associated with assembled neurofilaments or with other cytoskeletal components, and not with the phosphatase used.
D002846:Chromatography, Affinity; D002918:Chymotrypsin / Q000378:metabolism; D003101:Collodion; D003599:Cytoskeleton / Q000378:metabolism; D004355:Drug Stability; D004591:Electrophoresis, Polyacrylamide Gel; D007381:Intermediate Filament Proteins / Q000378:metabolism*; D016900:Neurofilament Proteins; D010209:Paper; D010744:Phosphoric Monoester Hydrolases / Q000378:metabolism; D010766:Phosphorylation
D007381:Intermediate Filament Proteins; D016900:Neurofilament Proteins; D003101:Collodion; D010744:Phosphoric Monoester Hydrolases; D002918:Chymotrypsin