title: DNA unwinding by ASCC3 helicase is coupled to ALKBH3-dependent DNA alkylation repair and cancer cell proliferation.
abstract: Demethylation by the AlkB dioxygenases represents an important mechanism for repair of N-alkylated nucleotides. However, little is known about their functions in mammalian cells. We report the purification of the ALKBH3 complex and demonstrate its association with the activating signal cointegrator complex (ASCC). ALKBH3 is overexpressed in various cancers, and both ALKBH3 and ASCC are important for alkylation damage resistance in these tumor cell lines. ASCC3, the largest subunit of ASCC, encodes a 3'-5' DNA helicase, whose activity is crucial for the generation of single-stranded DNA upon which ALKBH3 preferentially functions for dealkylation. In cell lines that are dependent on ALKBH3 and ASCC3 for alkylation damage resistance, loss of ALKBH3 or ASCC3 leads to increased 3-methylcytosine and reduced cell proliferation, which correlates with pH2A.X and 53BP1 foci formation. Our data provide a molecular mechanism by which ALKBH3 collaborates with ASCC to maintain genomic integrity in a cell-type specific manner.
authors: Division of Newborn Medicine and Epigenetics Program, Department of Medicine, Children's Hospital Boston, Harvard Medical School, Boston, MA 02115, USA.
authors: Sebastian
authors: S
authors: Dango
authors: Nima
authors: N
authors: Mosammaparast
authors: Mathew E
authors: ME
authors: Sowa
authors: Li-Jun
authors: LJ
authors: Xiong
authors: Feizhen
authors: F
authors: Wu
authors: Keyjung
authors: K
authors: Park
authors: Mark
authors: M
authors: Rubin
authors: Steve
authors: S
authors: Gygi
authors: J Wade
authors: JW
authors: Harper
authors: Yang
authors: Y
authors: Shi
mesh_terms: D000071500:AlkB Homolog 3, Alpha-Ketoglutarate-Dependent Dioxygenase; D000478:Alkylation; D000818:Animals; D018906:Antineoplastic Agents, Alkylating / Q000494:pharmacology; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D004265:DNA Helicases / Q000235:genetics / Q000378:metabolism*; D004260:DNA Repair; D045643:DNA Repair Enzymes / Q000235:genetics / Q000378:metabolism*; D049308:Dioxygenases / Q000235:genetics / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D057809:HEK293 Cells; D006657:Histones / Q000378:metabolism; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins / Q000378:metabolism; D008297:Male; D008741:Methyl Methanesulfonate; D051379:Mice; D016688:Mice, Inbred NOD; D009154:Mutation; D009368:Neoplasm Transplantation; D010766:Phosphorylation; D011471:Prostatic Neoplasms / Q000201:enzymology* / Q000235:genetics / Q000473:pathology; D034622:RNA Interference; D013997:Time Factors; D014162:Transfection; D047368:Tumor Burden; D000071857:Tumor Suppressor p53-Binding Protein 1
chemical_list: D018906:Antineoplastic Agents, Alkylating; C468783:H2AX protein, human; D006657:Histones; D047908:Intracellular Signaling Peptides and Proteins; C498301:TP53BP1 protein, human; D000071857:Tumor Suppressor p53-Binding Protein 1; D008741:Methyl Methanesulfonate; D049308:Dioxygenases; C486439:ALKBH3 protein, human; D000071500:AlkB Homolog 3, Alpha-Ketoglutarate-Dependent Dioxygenase; D004265:DNA Helicases; D045643:DNA Repair Enzymes