Mechanism of translational control by hemin in reticulocyte lysates

Datta, A. ; de Haro, C. ; Sierra, J. M. ; Ochoa, S. (1977) Mechanism of translational control by hemin in reticulocyte lysates Proceedings of the National Academy of Sciences of the United States of America, 74 (8). pp. 3326-3329. ISSN 0027-8424

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The formation of translational inhibitor (active eIF-2 kinase) from proinhibitor (inactive eIF-2 kinase) in reticulocyte lysates, known to be controlled by hemin, can, as we recently reported, be induced by 3':5'-cyclic AMP(cAMP)-dependent protein kinase (ATP:protein phosphotransferase, EC or its catalytic subunit. We find that in crude preparations from rabbit reticulocyte lysates, hemin inhibits the conversion of proinhibitor to inhibitor catalyzed by endogenous cAMP-dependent protein kinase upon addition of cAMP, but not that caused by the addition of free protein kinase catalytic subunit. Hemin prevents the binding of cAMP to the regulatory subunit of cAMP-dependent protein kinase and blocks the cAMP-induced dissociation of regulatory and catalytic subunits of the enzyme whereby the enzyme is inactivated. The mechanism by which hemin prevents the formation of the inhibitor and maintains protein synthesis in reticulocyte lysates is thus explained.

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ID Code:9326
Deposited On:02 Nov 2010 12:29
Last Modified:16 May 2016 19:09

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