Protein arginylation in rat brain cytosol: a proteomic analysis.
Arginine can be post-translationally incorporated from arginyl-tRNA into the N-terminus of soluble acceptor proteins in a reaction catalyzed by arginyl-tRNA protein transferase. In the present study, several soluble rat brain proteins that accepted arginine were identified after arginine incorporation by two dimensional electrophoresis and mass spectrometry. They were identified as: contrapsin-like protease inhibitor-3, alpha-1-antitrypsin, apolipoprotein E, hemopexin, calreticulin and apolipoprotein A-I. All of these proteins shared a signal sequence for the translocation of proteins across endoplasmic reticulum membranes. After losing the signal peptide, these proteins expose amino acids described as compatible for post-translational arginylation. Although the enzymatic system involved in arginylation is confined mainly in cytosol and nucleus, all the substrates described herein enter to the exocytic pathway co-translationally. Therefore, we postulate that the substrates for arginylation could reach the cytosol by retro-translocation and be then arginylated.
Decca
María Belén
MB
Centro de Investigaciones en Química Biológica de Córdoba, CIQUIBIC, (UNC-CONICET), Departamento de Química Biológica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, 5000, Córdoba, Argentina.
Bosc
Christophe
C
Luche
Sylvie
S
Brugière
Sabine
S
Job
Didier
D
Rabilloud
Thierry
T
Garin
Jerôme
J
Hallak
Marta Elena
ME
D000818:Animals; D001120:Arginine / Q000378:metabolism*; D001921:Brain / Q000378:metabolism*; D003600:Cytosol / Q000378:metabolism*; D015180:Electrophoresis, Gel, Two-Dimensional; D066298:In Vitro Techniques; D011499:Protein Processing, Post-Translational; D021381:Protein Transport; D020543:Proteome / Q000378:metabolism*; D051381:Rats; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
D020543:Proteome; D001120:Arginine