Expression of the catalytic subunits of pol alpha and pol delta from fission yeast Schizosaccharomyces pombe.
This paper reports on expression and posttranslational modifications of the catalytic subunits of pol alpha and pol delta from fission yeast Schizosaccharomyces pombe. Okadaic acid treatment of S. pombe spheroplasts in amounts known to inhibit phosphatases 1 and 2A resulted in decreased proteolysis of both pol alpha and pol delta. Computer analysis of pol alpha and pol delta sequences confirmed the presence of consensus motifs for protein phosphorylation. Indirect immunofluorescence microscopy of S. pombe cells showed nuclear location of both proteins in wild type cells. However, whereas cells transformed with a vector expressing pol alpha produced a clear increase of the nuclear signal, no increase was detectable in cells transformed with pol delta. This observation suggests the existence of a mechanism limiting the cell concentration of pol delta in the cell. Constitutive expression of S. pombe pol delta in E. coli was possible only with vectors containing truncated forms of its gene, indicating a toxic effect of pol delta on E. coli growth.
Pignède
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Biologie Moléculaire de la Réplication, UPR 272 CNRS, Villejuif, France.
Moussy
G
G
Bouvier
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D
Tillit
J
J
de Recondo
A M
AM
Baldacci
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G
D000595:Amino Acid Sequence; D003062:Codon; D004257:DNA Polymerase II / Q000378:metabolism*; D004258:DNA Polymerase III; D004259:DNA-Directed DNA Polymerase / Q000378:metabolism*; D004926:Escherichia coli / Q000235:genetics; D015971:Gene Expression Regulation, Enzymologic; D015966:Gene Expression Regulation, Fungal; D008856:Microscopy, Fluorescence; D008969:Molecular Sequence Data; D010766:Phosphorylation; D011994:Recombinant Proteins / Q000096:biosynthesis; D012568:Schizosaccharomyces / Q000201:enzymology*; D013347:Subcellular Fractions / Q000201:enzymology
D003062:Codon; D011994:Recombinant Proteins; D004257:DNA Polymerase II; D004258:DNA Polymerase III; D004259:DNA-Directed DNA Polymerase