This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via CrossRef Citing Articles via Google Scholar Google Scholar Articles by Browning, K. S. Articles by Ravel, J. M. Search for Related Content PubMed PubMed Citation Articles by Browning, K. S. Articles by Ravel, J. M. Agricola Articles by Browning, K. S. Articles by Ravel, J. M.

Articles

Phosphorylation of Wheat Germ Initiation Factors and Ribosomal Proteins ¹

Department of Biological Chemistry, College of Medicine, University of Illinois at Chicago, Chicago, Illinois 60612, Department of Chemistry and Clayton Foundation Biochemical Institute, University of Texas at Austin, Austin, Texas 78712

The ability of the wheat germ initiation factors and ribosomes to serve as substrates for a wheat germ protein kinase (Yan and Tao 1982 J Biol Chem 257: 7037-7043) has been investigated. The wheat germ kinase catalyzes the phosphorylation of the 42,000 dalton subunit of eukaryotic initiation factor (eIF)-2 and the 107,000 dalton subunit of eIF-3. Other initiation factors, eIF-4B and eIF-4A, and elongation factors, EF-1 and EF-2, are not phosphorylated by the kinase. Quantitative analysis indicates that the kinase catalyzes the incorporation of about 0.5 to 0.6 mole of phosphate per mole of the 42,000 dalton subunit of eIF-2 and about 6 moles of phosphate per mole of the 107,000 dalton subunit of eIF-3. Three proteins (M_r = 38,000, 14,800, and 12,600) of the 60S ribosomal subunit are phosphorylated by the kinase, but none of the 40S ribosomal proteins are substrates of the kinase. No effects of phosphorylation on the activities of eIF-2, eIF-3, or 60S ribosomal subunits could be demonstrated in vitro.

This article has been cited by other articles:

				J. O. Langland, L. A. Langland, K. S. Browning, and D. A. Roth Phosphorylation of Plant Eukaryotic Initiation Factor-2 by the Plant-encoded Double-stranded RNA-dependent Protein Kinase, pPKR, and Inhibition of Protein Synthesis in Vitro J. Biol. Chem., February 23, 1996; 271(8): 4539 - 4544. [Abstract] [Full Text] [PDF]