title: Evidence for highly stable nuclear poly(A) in cultured mammalian cells.
abstract: The kinetics of turnover of nuclear poly(A) were determined under conditions which facilitated the detection of relatively stable classes of the molecule. Growing 3T6 or HeLa cells were labeled with [3H]adenosine for several hours. The turnover of nuclear poly(A) was then followed over long time intervals using a variety of chase conditions. When a cordycepin chase was employed, a class of nuclear poly(A) with a half life of 2.5 h was observed. When the chase was effected by allowing the intracellular ATP pool specific activity to decay as a result of normal metabolic processes, a more stable class of nuclear poly(A) was detected (half life = 8--12 h). These results indicate that a significant portion of poly(A)-hnRNA has a long half-life.
mesh_terms: D002460:Cell Line; D002467:Cell Nucleus / Q000378:metabolism*; D002478:Cells, Cultured; D003470:Culture Media; D003839:Deoxyadenosines / Q000494:pharmacology; D006367:HeLa Cells; D007042:Hypoxanthines / Q000494:pharmacology; D008970:Molecular Weight; D011061:Poly A / Q000378:metabolism*; D012313:RNA / Q000378:metabolism*
chemical_list: D003470:Culture Media; D003839:Deoxyadenosines; D007042:Hypoxanthines; D011061:Poly A; D012313:RNA