title: ADP is a substrate for the AAUAAA-directed poly(A) addition reaction catalyzed by HeLa cell nuclear extracts.
abstract: The specific poly(A) addition reaction catalyzed by crude nuclear extracts from HeLa cells can use ADP as efficiently as ATP as the donor of AMP residues. Both the ADP- and ATP-supported reactions require an intact upstream polyadenylation signal sequence element (AAUAAA). The mutated signal sequence (AACAAA) supports neither reaction. The ADP-supported poly(A) addition reaction can be resolved by glycerol gradient centrifugation of the crude nuclear extract into two components which are active when recombined but are inactive individually. The ATP-supported poly(A) addition is reconstituted by recombining the same gradient fractions, but the activity is lower than that supported by ADP, suggesting that an ATP-specific factor has been removed. A 150 mM KCl fraction DEAE-Sepharose of the nuclear extract, also devoid of the ATP-supported poly(A) addition reaction, retains a normal ADP-supported reaction. Together, these data show that ADP is a substrate for polyadenylation, and suggest that different factors might be required to induce ADP- or ATP-specificity in the poly(A) addition reaction.
authors.affiliation: Cancer Research Institute, Slovak Academy of Sciences, Bratislava, Czechoslovakia.
authors.forename: J
authors.initials: J
authors.lastname: Lakota
authors.forename: B D
authors.initials: BD
authors.lastname: Nelson
mesh_terms: D000244:Adenosine Diphosphate / Q000378:metabolism*; D000255:Adenosine Triphosphate / Q000378:metabolism; D001483:Base Sequence; D002467:Cell Nucleus / Q000378:metabolism* / Q000648:ultrastructure; D002499:Centrifugation, Density Gradient; D006367:HeLa Cells / Q000378:metabolism; D006801:Humans; D009843:Oligoribonucleotides; D011061:Poly A / Q000378:metabolism*; D011062:Polynucleotide Adenylyltransferase / Q000378:metabolism; D012322:RNA Precursors / Q000378:metabolism
chemical_list: D009843:Oligoribonucleotides; D012322:RNA Precursors; D011061:Poly A; D000244:Adenosine Diphosphate; D000255:Adenosine Triphosphate; D011062:Polynucleotide Adenylyltransferase