Treatment of cells with the angiogenic inhibitor fumagillin results in increased stability of eukaryotic initiation factor 2-associated glycoprotein, p67, and reduced phosphorylation of extracellular signal-regulated kinases.
Fumagillin, an angiogenic inhibitor, binds to methionine aminopeptidase 2, which is the same as eukaryotic initiation factor 2-associated glycoprotein, p67. p67 protects eIF2alpha from phosphorylation by its kinases. To understand the importance of fumagillin binding to p67, we measured the level of p67 in mouse C2C12 myoblasts treated with fumagillin. We show that fumagillin increases the stability of p67 by decreasing its turnover rate. The increased levels of p67 result in inhibition of phosphorylation of extracellular signal-regulated kinases 1 and 2 (ERKs 1 and 2). p67 binds to these ERKs, and the 108-480 amino acid segment is sufficient for this binding. p67's affinity to ERKs 1 and 2 also increases in fumagillin-treated myoblasts while its affinity for eIF2alpha remains unchanged. A mutant at the conserved amino acid residue D251A increases the phosphorylation of ERKs 1 and 2 without affecting the binding to p67, thus indicating the importance of this residue in the regulation of the phosphorylation of these ERKs. These results suggest that fumagillin increases the stability of p67 and its affinity to ERKs 1 and 2 and causes the inhibition of the phosphorylation of ERKs 1 and 2.
Datta
Bansidhar
B
Department of Chemistry, Kent State University, Kent, Ohio 44242, USA. bdatta@kent.edu
Majumdar
Avijit
A
Datta
Rekha
R
Balusu
Ramesh
R
D000409:Alanine / Q000235:genetics; D019943:Amino Acid Substitution / Q000235:genetics; D000626:Aminopeptidases / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism*; D020533:Angiogenesis Inhibitors / Q000378:metabolism / Q000494:pharmacology*; D000818:Animals; D001224:Aspartic Acid / Q000235:genetics; D002460:Cell Line; D003510:Cyclohexanes; D004791:Enzyme Inhibitors / Q000378:metabolism; D004795:Enzyme Stability / Q000187:drug effects / Q000235:genetics; D015852:Eukaryotic Initiation Factor-2 / Q000378:metabolism*; D005231:Fatty Acids, Unsaturated / Q000378:metabolism / Q000494:pharmacology*; D005260:Female; D006023:Glycoproteins / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism*; D020128:Inhibitory Concentration 50; D063208:Methionyl Aminopeptidases; D051379:Mice; D008807:Mice, Inbred BALB C; D019950:Mitogen-Activated Protein Kinase 1 / Q000037:antagonists & inhibitors / Q000378:metabolism*; D048052:Mitogen-Activated Protein Kinase 3 / Q000037:antagonists & inhibitors / Q000378:metabolism*; D032448:Myoblasts, Skeletal / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism; D010446:Peptide Fragments / Q000378:metabolism; D010766:Phosphorylation / Q000187:drug effects; D011485:Protein Binding / Q000187:drug effects / Q000235:genetics; D012717:Sesquiterpenes; D014162:Transfection
D020533:Angiogenesis Inhibitors; D003510:Cyclohexanes; D004791:Enzyme Inhibitors; D015852:Eukaryotic Initiation Factor-2; D005231:Fatty Acids, Unsaturated; D006023:Glycoproteins; D010446:Peptide Fragments; D012717:Sesquiterpenes; D001224:Aspartic Acid; C026211:fumagillin; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D000626:Aminopeptidases; C489894:Metap2 protein, mouse; D063208:Methionyl Aminopeptidases; D000409:Alanine