Hydroxyurea-Mediated Cytotoxicity Without Inhibition of Ribonucleotide Reductase.
In many organisms, hydroxyurea (HU) inhibits class I ribonucleotide reductase, leading to lowered cellular pools of deoxyribonucleoside triphosphates. The reduced levels for DNA precursors is believed to cause replication fork stalling. Upon treatment of the hyperthermophilic archaeon Sulfolobus solfataricus with HU, we observe dose-dependent cell cycle arrest, accumulation of DNA double-strand breaks, stalled replication forks, and elevated levels of recombination structures. However, Sulfolobus has a HU-insensitive class II ribonucleotide reductase, and we reveal that HU treatment does not significantly impact cellular DNA precursor pools. Profiling of protein and transcript levels reveals modulation of a specific subset of replication initiation and cell division genes. Notably, the selective loss of the regulatory subunit of the primase correlates with cessation of replication initiation and stalling of replication forks. Furthermore, we find evidence for a detoxification response induced by HU treatment.
Sir William Dunn School of Pathology, South Parks Road, Oxford OX1 3RE, UK.
Li Phing
LP
Liew
Department of Molecular and Cellular Biochemistry, Indiana University, Simon Hall MSB, 212 South Hawthorne Drive, Bloomington, IN 47405, USA.
Zun Yi
ZY
Lim
Department of Biology, Indiana University, Simon Hall MSB, 212 South Hawthorne Drive, Bloomington, IN 47405, USA.
Matan
M
Cohen
Department of Medical Biochemistry and Biophysics, Umeå University, SE 90197 Umeå, Sweden.
Ziqing
Z
Kong
Department of Medical Biochemistry and Biophysics, Umeå University, SE 90197 Umeå, Sweden.
Lisette
L
Marjavaara
Department of Medical Biochemistry and Biophysics, Umeå University, SE 90197 Umeå, Sweden; Laboratory for Molecular Infection Medicine Sweden, Umeå University, SE 90197 Umeå, Sweden.
Andrei
A
Chabes
Department of Molecular and Cellular Biochemistry, Indiana University, Simon Hall MSB, 212 South Hawthorne Drive, Bloomington, IN 47405, USA; Department of Biology, Indiana University, Simon Hall MSB, 212 South Hawthorne Drive, Bloomington, IN 47405, USA. Electronic address: stedbell@indiana.edu.
Stephen D
SD
Bell
D001426:Bacterial Proteins / Q000378:metabolism; D002455:Cell Division / Q000187:drug effects; D019915:DNA Primase / Q000378:metabolism; D004261:DNA Replication / Q000187:drug effects; D019641:DNA, Archaeal / Q000378:metabolism; D019848:Gene Expression Regulation, Archaeal / Q000187:drug effects; D006918:Hydroxyurea / Q000494:pharmacology*; D009711:Nucleotides / Q000378:metabolism; D021122:Protein Subunits / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D012264:Ribonucleotide Reductases / Q000037:antagonists & inhibitors* / Q000378:metabolism; D013379:Substrate Specificity / Q000187:drug effects; D016944:Sulfolobus / Q000166:cytology / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development; D014158:Transcription, Genetic / Q000187:drug effects
D001426:Bacterial Proteins; D019641:DNA, Archaeal; D009711:Nucleotides; D021122:Protein Subunits; D012333:RNA, Messenger; D012264:Ribonucleotide Reductases; D019915:DNA Primase; D006918:Hydroxyurea
DNA damage; DNA replication; Sulfolobus; archaea; hydroxyurea; replication fork