Nuclear envelope glycoprotein with poly(A) polymerase activity of rat liver: isolation, characterization, and immunohistochemical localization.
A protein with poly(A) polymerase activity has been identified and isolated from hepatic nuclear envelopes of rats to near homogeneity. The ability of the enzyme to bind to concanavalin A-agarose and to be eluted from the column with methyl alpha-D-mannopyranoside (0.2 M) as well as the inhibitory effects of alpha-mannosidase suggested that it was a glycoprotein. Poly(A) polymerase has an absolute requirement for a divalent cation, ATP, and an oligonucleotide primer. The enzyme activity with Mn2+ was about 20-fold higher than that with Mg2+. Several known inhibitors adversely affected poly(A) polymerase activity. The enzyme has a molecular weight of 64,000 when analyzed by polyacrylamide gel electrophoresis under denaturing conditions and has a sedimentation coefficient of 4.5 S. Immunohistochemical studies using polyclonal antibodies raised against the purified enzyme revealed that the antigen was localized in the nuclear membranes.
Kurl
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RN
Department of Pathology, George Washington University Medical Center, Washington, D.C. 20037.
Holmes
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SC
Verney
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Sidransky
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H
D000255:Adenosine Triphosphate / Q000494:pharmacology; D000818:Animals; D002413:Cations, Divalent; D002846:Chromatography, Affinity; D003208:Concanavalin A; D004591:Electrophoresis, Polyacrylamide Gel; D007150:Immunohistochemistry; D008099:Liver / Q000648:ultrastructure*; D008562:Membrane Glycoproteins / Q000032:analysis / Q000378:metabolism; D008970:Molecular Weight; D009685:Nuclear Envelope / Q000201:enzymology*; D009713:Nucleotidyltransferases / Q000032:analysis / Q000378:metabolism; D009841:Oligonucleotides / Q000494:pharmacology; D011062:Polynucleotide Adenylyltransferase / Q000032:analysis / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains; D015032:Zinc / Q000494:pharmacology
D002413:Cations, Divalent; D008562:Membrane Glycoproteins; D009841:Oligonucleotides; D003208:Concanavalin A; D000255:Adenosine Triphosphate; D009713:Nucleotidyltransferases; D011062:Polynucleotide Adenylyltransferase; D015032:Zinc