title: Actin--an inhibitor of eukaryotic elongation factor activities.
abstract: An inhibitor of diphtheria toxin- and endogenous transferase-dependent ADP-ribosylation of eukaryotic elongation factor 2 (eEF2) has been found in the cytoplasmic fraction from rat liver. We provide evidence that this cytoplasmic inhibitor corresponds to actin, which gives rise also to inhibition of polyphenylalanine (polyPhe) synthesis. Both globular monomeric (G-actin) and filamentous (F-actin) forms of actin appear to be inhibitory on the action of elongation factors 1 and 2 (eEF1 and eEF2) in polyPhe synthesis with the inhibitory effect of G-actin proving to be stronger. Some component(s) in the postribosomal supernatant (S-130) fraction and also DNase I prevent actin-promoted inhibition of polyPhe synthesis.
authors.affiliation: Biophysics Department, Istanbul Faculty of Medicine, Istanbul University, 34390, Capa, Istanbul, Turkey. muhbektas@hotmail.com
authors.forename: Muhammet
authors.initials: M
authors.lastname: Bektaş
authors.forename: Başak
authors.initials: B
authors.lastname: Günçer
authors.forename: Celal
authors.initials: C
authors.lastname: Güven
authors.forename: Rüstem
authors.initials: R
authors.lastname: Nurten
authors.forename: Engin
authors.initials: E
authors.lastname: Bermek
mesh_terms: D036002:ADP Ribose Transferases / Q000378:metabolism; D000199:Actins / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000494:pharmacology*; D000246:Adenosine Diphosphate Ribose / Q000037:antagonists & inhibitors / Q000378:metabolism; D000818:Animals; D003600:Cytosol / Q000378:metabolism; D003850:Deoxyribonuclease I / Q000494:pharmacology; D004167:Diphtheria Toxin / Q000037:antagonists & inhibitors / Q000378:metabolism / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D022781:Hepatocytes / Q000737:chemistry; D020128:Inhibitory Concentration 50; D018482:Muscle, Skeletal / Q000737:chemistry; D020648:Peptide Elongation Factor 1 / Q000037:antagonists & inhibitors*; D020652:Peptide Elongation Factor 2 / Q000037:antagonists & inhibitors*; D010455:Peptides / Q000037:antagonists & inhibitors / Q000378:metabolism; D011817:Rabbits; D051381:Rats; D012270:Ribosomes / Q000378:metabolism
chemical_list: D000199:Actins; D004167:Diphtheria Toxin; D020648:Peptide Elongation Factor 1; D020652:Peptide Elongation Factor 2; D010455:Peptides; D000246:Adenosine Diphosphate Ribose; C012001:polyphenylalanine; D036002:ADP Ribose Transferases; D003850:Deoxyribonuclease I