title: The interaction between ALKBH2 DNA repair enzyme and PCNA is direct, mediated by the hydrophobic pocket of PCNA and perturbed in naturally-occurring ALKBH2 variants.
abstract: Human AlkB homolog 2 (ALKBH2) is a DNA repair enzyme that catalyzes the direct reversal of DNA methylation damage through oxidative demethylation. While ALKBH2 colocalizes with proliferating cell nuclear antigen (PCNA) in DNA replication foci, it remains unknown whether these two proteins alone form a complex or require additional components for interaction. Here, we demonstrate that ALKBH2 can directly interact with PCNA independent from other cellular factors, and we identify the hydrophobic pocket of PCNA as the key domain mediating this interaction. Moreover, we find that PCNA association with ALKBH2 increases significantly during DNA replication, suggesting that ALKBH2 forms a cell-cycle dependent complex with PCNA. Intriguingly, we show that an ALKBH2 germline variant, as well as a variant found in cancer, display altered interaction with PCNA. Our studies reveal the ALKBH2 binding interface of PCNA and indicate that both germline and somatic ALKBH2 variants could have cellular effects on ALKBH2 function in DNA repair.
authors.affiliation: Institute of Veterinary Biochemistry and Molecular Biology, University of Zürich, Winterthurerstrasse 190, 8057 Zürich, Switzerland. Electronic address: dragonyfu@rochester.edu.
authors.forename: Dragony
authors.initials: D
authors.lastname: Fu
authors.affiliation: Department of Biological Engineering and Biology, Center for Environmental Health Sciences, David H. Koch Center for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
authors.forename: Leona D
authors.initials: LD
authors.lastname: Samson
authors.affiliation: Institute of Veterinary Biochemistry and Molecular Biology, University of Zürich, Winterthurerstrasse 190, 8057 Zürich, Switzerland.
authors.forename: Ullrich
authors.initials: U
authors.lastname: Hübscher
authors.affiliation: Institute of Veterinary Biochemistry and Molecular Biology, University of Zürich, Winterthurerstrasse 190, 8057 Zürich, Switzerland. Electronic address: bvanloon@vetbio.uzh.ch.
authors.forename: Barbara
authors.initials: B
authors.lastname: van Loon
mesh_terms: D000071499:AlkB Homolog 2, Alpha-Ketoglutarate-Dependent Dioxygenase; D019943:Amino Acid Substitution; D004260:DNA Repair; D045643:DNA Repair Enzymes / Q000737:chemistry* / Q000235:genetics; D004261:DNA Replication; D049308:Dioxygenases / Q000737:chemistry* / Q000235:genetics; D018095:Germ-Line Mutation; D057809:HEK293 Cells; D006801:Humans; D057927:Hydrophobic and Hydrophilic Interactions; D009369:Neoplasms / Q000235:genetics / Q000378:metabolism; D018809:Proliferating Cell Nuclear Antigen / Q000737:chemistry* / Q000235:genetics; D020033:Protein Isoforms / Q000737:chemistry / Q000235:genetics; D017434:Protein Structure, Tertiary; D016196:S Phase
chemical_list: D018809:Proliferating Cell Nuclear Antigen; D020033:Protein Isoforms; D049308:Dioxygenases; C486440:ALKBH2 protein, human; D000071499:AlkB Homolog 2, Alpha-Ketoglutarate-Dependent Dioxygenase; D045643:DNA Repair Enzymes
keywords: ALKBH2; APIM; AlkB; DNA repair; PCNA