Abstract
We have reported previously that calcium ions and phospholipid activate the heme-stabilized proinhibitor form (pro-HCI) of the heme-controlled translational inhibitor (HCI) in reticulocyte lysates and promote the first step of the reaction pro-HCI in equilibrium reversible HCI----irreversible HCI. This suggested the possible involvement of a Ca2+/phospholipid-dependent protein kinase (protein kinase C) in the activation. However, further investigation revealed, among other things, that polyunsaturated fatty acids (e.g., arachidonic acid) were as effective as Ca2+/phospholipid in promoting translational inhibition and phosphorylation of the alpha subunit of the chain-initiation factor eIF-2 and, moreover, HCI activation could be prevented or reversed in either case by NADPH-generating systems or by dithiols. Our results suggest that pro-HCI is activated by lipoperoxides produced in reticulocyte lysates from either phospholipid or polyunsaturated fatty acids; the presence of Ca2+ is required in the former but not in the latter case. The reversible activation of HCI by Ca2+ and phospholipid might suggest a possible modulatory role of Ca2+ in translational control.
Full text
PDF




Images in this article
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Brot N., Weissbach H. Biochemistry and physiological role of methionine sulfoxide residues in proteins. Arch Biochem Biophys. 1983 May;223(1):271–281. doi: 10.1016/0003-9861(83)90592-1. [DOI] [PubMed] [Google Scholar]
- Buege J. A., Aust S. D. Microsomal lipid peroxidation. Methods Enzymol. 1978;52:302–310. doi: 10.1016/s0076-6879(78)52032-6. [DOI] [PubMed] [Google Scholar]
- Datta A., de Haro C., Sierra J. M., Ochoa S. Role of 3':5'-cyclic-AMP-dependent protein kinase in regulation of protein synthesis in reticulocyte lysates. Proc Natl Acad Sci U S A. 1977 Apr;74(4):1463–1467. doi: 10.1073/pnas.74.4.1463. [DOI] [PMC free article] [PubMed] [Google Scholar]
- De Haro C., De Herreros A. G., Ochoa S. Activation of the heme-stabilized translational inhibitor of reticulocyte lysates by calcium ions and phospholipid. Proc Natl Acad Sci U S A. 1983 Nov;80(22):6843–6847. doi: 10.1073/pnas.80.22.6843. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Kawaguchi A., Bloch K. Inhibition of glucose 6-phosphate dehydrogenase by palmitoyl coenzyme A. J Biol Chem. 1974 Sep 25;249(18):5793–5800. [PubMed] [Google Scholar]
- Matts R. L., Levin D. H., London I. M. Effect of phosphorylation of the alpha-subunit of eukaryotic initiation factor 2 on the function of reversing factor in the initiation of protein synthesis. Proc Natl Acad Sci U S A. 1983 May;80(9):2559–2563. doi: 10.1073/pnas.80.9.2559. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Ochoa S. Regulation of protein synthesis initiation in eucaryotes. Arch Biochem Biophys. 1983 Jun;223(2):325–349. doi: 10.1016/0003-9861(83)90598-2. [DOI] [PubMed] [Google Scholar]
- Rapoport S. M., Schewe T., Wiesner R., Halangk W., Ludwig P., Janicke-Höhne M., Tannert C., Hiebsch C., Klatt D. The lipoxygenase of reticulocytes. Purification, characterization and biological dynamics of the lipoxygenase; its identity with the respiratory inhibitors of the reticulocyte. Eur J Biochem. 1979 Jun 1;96(3):545–561. doi: 10.1111/j.1432-1033.1979.tb13068.x. [DOI] [PubMed] [Google Scholar]
- Schatzman R. C., Raynor R. L., Fritz R. B., Kuo J. F. Purification to homogeneity, characterization and monoclonal antibodies of phospholipid-sensitive Ca2+-dependent protein kinase from spleen. Biochem J. 1983 Feb 1;209(2):435–443. doi: 10.1042/bj2090435. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Siekierka J., Manne V., Ochoa S. Mechanism of translational control by partial phosphorylation of the alpha subunit of eukaryotic initiation factor 2. Proc Natl Acad Sci U S A. 1984 Jan;81(2):352–356. doi: 10.1073/pnas.81.2.352. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Takai Y., Kishimoto A., Iwasa Y., Kawahara Y., Mori T., Nishizuka Y. Calcium-dependent activation of a multifunctional protein kinase by membrane phospholipids. J Biol Chem. 1979 May 25;254(10):3692–3695. [PubMed] [Google Scholar]
- Thomas N. S., Matts R. L., Petryshyn R., London I. M. Distribution of reversing factor in reticulocyte lysates during active protein synthesis and on inhibition by heme deprivation or double-stranded RNA. Proc Natl Acad Sci U S A. 1984 Nov;81(22):6998–7002. doi: 10.1073/pnas.81.22.6998. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Wise B. C., Raynor R. L., Kuo J. F. Phospholipid-sensitive Ca2+-dependent protein kinase from heart. I. Purification and general properties. J Biol Chem. 1982 Jul 25;257(14):8481–8488. [PubMed] [Google Scholar]


