2',5'-Oligoadenylate-dependent RNAse located in nuclei: biochemical characterization and subcellular distribution of the nuclease in human and murine cells.
A cellular fractionation procedure allowed the rapid preparation of membraneless nuclei which contained a 2',5'-oligoadenylate (2-5A)-binding activity which was not due to cytoplasmic contaminants. Purified nuclei prepared from human lymphocytic leukaemia cells and mouse fibroblasts were found to contain 20-22% of the total cellular enzyme. In contrast with the cytoplasmic enzyme which was only present in a 2-5A-free form, 75% of the 2-5A-binding activity was found in the nuclei after a denaturing-renaturing procedure as the 2-5A-binding site was masked. Although the purification of nuclei from mouse fibroblasts was less effective, it appeared that, in confluent and growing cells, 50% and 75% respectively of the 2-5A-binding site was masked. Additional findings obtained by partial proteolysis and two-dimensional gel analysis provided definitive data on the nuclear location of this enzyme. Study of the nuclear 2-5A-dependent RNAase with a 2-5A-masked site could lead to an understanding of the molecular pathway involved in single-stranded RNA stability.
Bayard
B A
BA
CNRS U.A., 530, Université Montpellier II, France.
Gabrion
J B
JB
D000818:Animals; D001921:Brain / Q000201:enzymology*; D002352:Carrier Proteins / Q000302:isolation & purification / Q000378:metabolism*; D002458:Cell Fractionation; D002460:Cell Line; D002467:Cell Nucleus / Q000201:enzymology*; D003600:Cytosol / Q000201:enzymology; D015180:Electrophoresis, Gel, Two-Dimensional; D004591:Electrophoresis, Polyacrylamide Gel; D004722:Endoribonucleases / Q000302:isolation & purification / Q000378:metabolism*; D006801:Humans; D007668:Kidney / Q000201:enzymology*; D008297:Male; D051379:Mice; D009841:Oligonucleotides / Q000378:metabolism; D010446:Peptide Fragments / Q000302:isolation & purification; D012260:Ribonucleases / Q000302:isolation & purification / Q000378:metabolism*; D013154:Spleen / Q000201:enzymology*; D013347:Subcellular Fractions / Q000201:enzymology; D014407:Tumor Cells, Cultured
D002352:Carrier Proteins; D009841:Oligonucleotides; D010446:Peptide Fragments; D004722:Endoribonucleases; D012260:Ribonucleases; C031956:2-5A-dependent ribonuclease