Decca María Belén, Bosc Christophe, Luche Sylvie, Brugière Sabine, Job Didier, Rabilloud Thierry, Garin Jerôme, Hallak Marta Elena
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.
Neurochem Res. 2006 Mar;31(3):401-9. doi: 10.1007/s11064-005-9037-z.
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.
精氨酸可以在精氨酰 - tRNA蛋白转移酶催化的反应中，从精氨酰 - tRNA经翻译后掺入可溶性受体蛋白的N端。在本研究中，通过二维电泳和质谱法在精氨酸掺入后鉴定出几种接受精氨酸的可溶性大鼠脑蛋白。它们被鉴定为：抗胰蛋白酶样蛋白酶抑制剂 - 3、α-1-抗胰蛋白酶、载脂蛋白E、血红素结合蛋白、钙网蛋白和载脂蛋白A-I。所有这些蛋白都具有用于蛋白质跨内质网膜转运的信号序列。在失去信号肽后，这些蛋白暴露了被描述为适合翻译后精氨酰化的氨基酸。尽管参与精氨酰化的酶系统主要局限于细胞质和细胞核中，但本文所述的所有底物都是共翻译进入外排途径的。因此，我们推测精氨酰化的底物可以通过逆向转运到达细胞质，然后进行精氨酰化。
