title: Activity and regulation of archaeal DNA alkyltransferase: conserved protein involved in repair of DNA alkylation damage.
abstract: Agents that form methylation adducts in DNA are highly mutagenic and carcinogenic, and organisms have evolved specialized cellular pathways devoted to their repair, including DNA alkyltransferases. These are proteins conserved in eucarya, bacteria and archaea, acting by a unique reaction mechanism, which leads to direct repair of DNA alkylation damage and irreversible protein alkylation. The alkylated form of DNA alkyltransferases is inactive, and in eukaryotes, it is rapidly directed to degradation. We report here in vitro and in vivo studies on the DNA alkyltransferase from the thermophilic archaeon Sulfolobus solfataricus (SsOGT). The development of a novel, simple, and sensitive fluorescence-based assay allowed a careful characterization of the SsOGT biochemical and DNA binding activities. In addition, transcriptional and post-translational regulation of SsOGT by DNA damage was studied. We show that although the gene transcription is induced by alkylating agent treatment, the protein is degraded in vivo by an alkylation-dependent mechanism. These experiments suggest a striking conservation, from archaea to humans, of this important pathway safeguarding genome stability.
authors.affiliation: Institute of Protein Biochemistry, Consiglio Nazionale delle Ricerche, Via P. Castellino 111, 80131 Naples, Italy.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Perugino
authors.forename: Antonella
authors.initials: A
authors.lastname: Vettone
authors.forename: Giuseppina
authors.initials: G
authors.lastname: Illiano
authors.forename: Anna
authors.initials: A
authors.lastname: Valenti
authors.forename: Maria C
authors.initials: MC
authors.lastname: Ferrara
authors.forename: Mosè
authors.initials: M
authors.lastname: Rossi
authors.forename: Maria
authors.initials: M
authors.lastname: Ciaramella
mesh_terms: D019883:Alkyl and Aryl Transferases / Q000235:genetics / Q000378:metabolism*; D000478:Alkylation / Q000502:physiology; D019843:Archaeal Proteins / Q000235:genetics / Q000378:metabolism*; D004249:DNA Damage / Q000502:physiology*; D004260:DNA Repair / Q000502:physiology*; D019641:DNA, Archaeal / Q000235:genetics / Q000378:metabolism*; D048229:Sulfolobus solfataricus / Q000201:enzymology* / Q000235:genetics
chemical_list: D019843:Archaeal Proteins; D019641:DNA, Archaeal; D019883:Alkyl and Aryl Transferases; C050956:DNA alkyltransferase