title: MAX is an epigenetic sensor of 5-carboxylcytosine and is altered in multiple myeloma.
abstract: The oncogenic transcription factor MYC and its binding partner MAX regulate gene expression by binding to DNA at enhancer-box (E-box) elements 5΄-CACGTG-3΄. In mammalian genomes, the central E-box CpG has the potential to be methylated at the 5-position of cytosine (5mC), or to undergo further oxidation to the 5-hydroxymethyl (5hmC), 5-formyl (5fC), or 5-carboxyl (5caC) forms. We find that MAX exhibits the greatest affinity for a 5caC or unmodified C-containing E-box, and much reduced affinities for the corresponding 5mC, 5hmC or 5fC forms. Crystallization of MAX with a 5caC modified E-box oligonucleotide revealed that MAX Arg36 recognizes 5caC using a 5caC-Arg-Guanine triad, with the next nearest residue to the carboxylate group being Arg60. In an analysis of >800 primary multiple myelomas, MAX alterations occurred at a frequency of ∼3%, more than half of which were single nucleotide substitutions affecting a basic clamp-like interface important for DNA interaction. Among these, arginines 35, 36 and 60 were the most frequently altered. In vitro binding studies showed that whereas mutation of Arg36 (R36W) or Arg35 (R35H/L) completely abolished DNA binding, mutation of Arg60 (R60Q) significantly reduced DNA binding, but retained a preference for the 5caC modified E-box. Interestingly, MAX alterations define a subset of myeloma patients with lower MYC expression and a better overall prognosis. Together these data indicate that MAX can act as a direct epigenetic sensor of E-box cytosine modification states and that local CpG modification and MAX variants converge to modulate the MAX-MYC transcriptional network.
authors.affiliation: Department of Biochemistry, Emory University School of Medicine, Atlanta, GA 30322, USA.
authors.forename: Dongxue
authors.initials: D
authors.lastname: Wang
authors.affiliation: Department of Biochemistry, Emory University School of Medicine, Atlanta, GA 30322, USA.
authors.forename: Hideharu
authors.initials: H
authors.lastname: Hashimoto
authors.affiliation: Department of Biochemistry, Emory University School of Medicine, Atlanta, GA 30322, USA.|Department of Molecular and Cellular Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA.
authors.forename: Xing
authors.initials: X
authors.lastname: Zhang
authors.affiliation: Department of Radiation Oncology, Emory University School of Medicine, Atlanta, GA 30322, USA.
authors.forename: Benjamin G
authors.initials: BG
authors.lastname: Barwick
authors.affiliation: Department of Hematology and Medical Oncology, Emory University School of Medicine, Atlanta, GA 30322, USA.|The Winship Cancer Institute of Emory University, Atlanta, GA 30322, USA.
authors.forename: Sagar
authors.initials: S
authors.lastname: Lonial
authors.affiliation: Department of Hematology and Medical Oncology, Emory University School of Medicine, Atlanta, GA 30322, USA.|The Winship Cancer Institute of Emory University, Atlanta, GA 30322, USA.
authors.forename: Lawrence H
authors.initials: LH
authors.lastname: Boise
authors.affiliation: Department of Radiation Oncology, Emory University School of Medicine, Atlanta, GA 30322, USA.|The Winship Cancer Institute of Emory University, Atlanta, GA 30322, USA.
authors.forename: Paula M
authors.initials: PM
authors.lastname: Vertino
authors.affiliation: Department of Biochemistry, Emory University School of Medicine, Atlanta, GA 30322, USA.|Department of Molecular and Cellular Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA.|The Winship Cancer Institute of Emory University, Atlanta, GA 30322, USA.
authors.forename: Xiaodong
authors.initials: X
authors.lastname: Cheng
mesh_terms: D001120:Arginine / Q000737:chemistry; D051778:Basic Helix-Loop-Helix Leucine Zipper Transcription Factors / Q000737:chemistry* / Q000235:genetics* / Q000378:metabolism; D018899:CpG Islands; D003596:Cytosine / Q000031:analogs & derivatives* / Q000737:chemistry / Q000378:metabolism; D004247:DNA / Q000737:chemistry / Q000378:metabolism; D024721:E-Box Elements; D044127:Epigenesis, Genetic; D009101:Multiple Myeloma / Q000235:genetics*; D009154:Mutation; D011485:Protein Binding; D011487:Protein Conformation; D012097:Repressor Proteins / Q000737:chemistry* / Q000235:genetics* / Q000378:metabolism
chemical_list: C560974:5-carboxylcytosine; D051778:Basic Helix-Loop-Helix Leucine Zipper Transcription Factors; C106465:MNT protein, human; D012097:Repressor Proteins; D003596:Cytosine; D004247:DNA; D001120:Arginine