title: Cordycepin analogs of ppp5'A2'p5'A2'p5'A (2-5A) inhibit protein synthesis through activation of the 2-5A-dependent endonuclease.
abstract: Analogs of the triphosphate 2'-5'-linked adenylate trimer (ppp5'A2'p5'A2'p5'A, called 2-5A) which contain 3'-deoxyadenosine (cordycepin) instead of adenosine either in positions one and two, or in all three positions, are 10-100-fold less potent than is parent 2-5A in inhibition of protein synthesis in intact cells, when utilizing calcium co-precipitation techniques to introduce the 5'-triphosphate oligonucleotides into the cells. That the inhibition of protein synthesis was a consequence of activation of the 2-5A-dependent endonuclease by the 3'-deoxyadenosine analogs of 2-5A was demonstrated in obtaining the ribosomal RNA cleavage pattern that is characteristic of endonuclease activation by parent 2-5A. Additional results (i.e. lack of activity by the dimer species ppp5'(3'dA)2'p5'-(3'dA) or the monomer 3'dA) as well as kinetic analysis both in intact cells and in cell-free extracts provided further evidence that the inhibition of protein synthesis observed with these 3'-deoxyadenosine 2-5A analogs was not due to their degradation to the antimetabolite monomer unit 3'-deoxyadenosine.
mesh_terms: D000818:Animals; D002460:Cell Line; D004722:Endoribonucleases / Q000378:metabolism*; D004789:Enzyme Activation; D007700:Kinetics; D051379:Mice; D009838:Oligodeoxyribonucleotides / Q000494:pharmacology*; D009841:Oligonucleotides / Q000494:pharmacology*; D014176:Protein Biosynthesis; D012335:RNA, Ribosomal / Q000032:analysis; D011817:Rabbits
chemical_list: C032558:2',5'-oligoadenylate cordycepin analog; D009838:Oligodeoxyribonucleotides; D009841:Oligonucleotides; D012335:RNA, Ribosomal; C033547:2'-5'-oligo(A)-dependent endonuclease; D004722:Endoribonucleases