Some common properties between a brain protein that is modified by posttranslational arginylation and the microtubule-associated STOP protein.
Properties so far studied of the 125-kDa 14C-arginylated protein from rat brain show remarkable similarities with those of the STOP (stable tubule only polypeptide) protein. On sodium dodecyl sulfate-polyacrylamide gel electrophoresis the 125-kDa 14C-arginylated protein moves to the same position as the STOP protein. The 125-kDa 14C-arginylated protein was immunoprecipitated by the monoclonal Mab 296 antibody specific for neuronal STOP protein. The 125-kDa 14C-arginylated protein was retained by a calmodulin column like STOP protein. As occurs with the STOP protein, the 125-kDa 14C-arginylated protein is found in higher proportion in cold-stable than in cold-labile microtubules. However, the modified protein associates with microtubules in a lower proportion than the STOP protein. We conclude that the STOP protein incorporates arginine by a posttranslational reaction but that only a small fraction of the STOP protein shows acceptor capacity in vitro.
CIQUIBIC, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Argentina.
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G
Bongiovanni
H S
HS
Barra
M E
ME
Hallak
D000818:Animals; D001120:Arginine / Q000378:metabolism*; D001921:Brain / Q000648:ultrastructure; D001923:Brain Chemistry; D002147:Calmodulin / Q000378:metabolism; D003080:Cold Temperature; D004591:Electrophoresis, Polyacrylamide Gel; D007163:Immunosorbent Techniques; D008869:Microtubule-Associated Proteins / Q000276:immunology / Q000378:metabolism*; D008870:Microtubules / Q000378:metabolism; D009419:Nerve Tissue Proteins / Q000378:metabolism*; D011499:Protein Processing, Post-Translational; D051381:Rats
D002147:Calmodulin; C113727:Map6 protein, rat; D008869:Microtubule-Associated Proteins; D009419:Nerve Tissue Proteins; D001120:Arginine