The subcellular distribution of poly-A-degrading activity in mouse kidney.
Most (95%) of the poly-A-degrading activity of the mouse kidney was found in the cytoplasmic fraction and only 5% was found in the nuclear fraction; 43% of the poly-A-degrading activity of the cytoplasm was found in the mitochondria, 22% in the microsomes, and 30% in the soluble fraction. Differences in activity and specificity indicate that poly A is degraded in the nucleus by enzymes that are separate and distinct from the enzymes in the cytoplasm that degrade poly A. The nuclear poly-A-degrading activity can be separated into an endonuclease with a general specificity and exonuclease, similar to one found in Ehrlich ascites tumor cells, which shows some specificity for poly A.
D000818:Animals; D002467:Cell Nucleus / Q000201:enzymology; D003600:Cytosol / Q000201:enzymology; D004720:Endonucleases / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D007668:Kidney / Q000201:enzymology*; D007700:Kinetics; D051379:Mice; D008861:Microsomes / Q000201:enzymology; D008928:Mitochondria / Q000201:enzymology; D011061:Poly A / Q000378:metabolism*; D012260:Ribonucleases / Q000378:metabolism*; D013347:Subcellular Fractions / Q000201:enzymology
D011061:Poly A; D004720:Endonucleases; D012260:Ribonucleases