Implication of mammalian ribosomal protein S3 in the processing of DNA damage.
A human apurinic/apyrimidinic endonuclease activity, called AP endonuclease I, is missing from or altered specifically in cells cultured from Xeroderma pigmentosum group-D individuals (XP-D cells) (Kuhnlein, U., Lee, B., Penhoet, E. E., and Linn, S. (1978) Nucleic Acids Res. 5,951-960). We have now observed that another nuclease activity, UV endonuclease III, is similarly not detected in XP-D cells and is inseparable from the AP endonuclease I activity. This activity preferentially cleaves the phosphodiester backbone of heavily ultraviolet-irradiated DNA at unknown lesions as well as at one of the phosphodiester bonds within a cyclobutane pyrimidine dimer. The nuclease activities have been purified from mouse cells to yield a peptide of M(r) = 32,000, whose sequence indicates identity with ribosomal protein S3. The nuclease activities all cross-react with immunopurified antibody directed against authentic rat ribosomal protein S3, and, upon expression in Escherichia coli of a cloned rat cDNA for ribosomal protein S3, each of the activities was recovered and was indistinguishable from those of the mammalian UV endonuclease III. Moreover, the protein expressed in E. coli and its activities cross-react with the rat protein antibody. Ribosomal protein S3 contains a potential nuclear localization signal, and the protein isolated as a nuclease also has a glycosylation pattern consistent with a nuclear localization as determined by lectin binding. The unexpected role of a ribosomal protein in DNA damage processing and the unexplained inability to detect the nuclease activities in extracts from XP-D cells are discussed.
Kim
J
J
Department of Molecular and Cell Biology, University of California, Berkeley 94720-3202, USA.
Chubatsu
L S
LS
Admon
A
A
Stahl
J
J
Fellous
R
R
Linn
S
S
D000595:Amino Acid Sequence; D002478:Cells, Cultured; D004247:DNA / Q000528:radiation effects; D004249:DNA Damage; D004260:DNA Repair; D043603:DNA-(Apurinic or Apyrimidinic Site) Lyase; D043223:Deoxyribonuclease IV (Phage T4-Induced); D004706:Endodeoxyribonucleases / Q000302:isolation & purification / Q000378:metabolism; D029968:Escherichia coli Proteins; D006801:Humans; D008190:Lyases / Q000378:metabolism; D008969:Molecular Sequence Data; D009097:Multienzyme Complexes / Q000302:isolation & purification / Q000378:metabolism; D009699:N-Glycosyl Hydrolases / Q000302:isolation & purification / Q000378:metabolism; D011740:Pyrimidine Dimers / Q000378:metabolism; D012269:Ribosomal Proteins / Q000378:metabolism*; D013379:Substrate Specificity; D014983:Xeroderma Pigmentosum / Q000201:enzymology
D029968:Escherichia coli Proteins; D009097:Multienzyme Complexes; D011740:Pyrimidine Dimers; D012269:Ribosomal Proteins; C044152:ribosomal protein S3; C032219:UV endonuclease; D004247:DNA; D004706:Endodeoxyribonucleases; D043223:Deoxyribonuclease IV (Phage T4-Induced); C468972:endonuclease IV, E coli; D009699:N-Glycosyl Hydrolases; D008190:Lyases; D043603:DNA-(Apurinic or Apyrimidinic Site) Lyase