Carboxylation of cytosine (5caC) in the CG dinucleotide in the E-box motif (CGCAG|GTG) increases binding of the Tcf3|Ascl1 helix-loop-helix heterodimer 10-fold.
Three oxidative products of 5-methylcytosine (5mC) occur in mammalian genomes. We evaluated if these cytosine modifications in a CG dinucleotide altered DNA binding of four B-HLH homodimers and three heterodimers to the E-Box motif CGCAG|GTG. We examined 25 DNA probes containing all combinations of cytosine in a CG dinucleotide and none changed binding except for carboxylation of cytosine (5caC) in the strand CGCAG|GTG. 5caC enhanced binding of all examined B-HLH homodimers and heterodimers, particularly the Tcf3|Ascl1 heterodimer which increased binding ~10-fold. These results highlight a potential function of the oxidative products of 5mC, changing the DNA binding of sequence-specific transcription factors.
Laboratory of Metabolism, National Cancer Institute, National Institutes of Health, Room 3128, Building 37, Bethesda, MD 20892, United States.
Jaya Prakash
JP
Golla
Laboratory of Metabolism, National Cancer Institute, National Institutes of Health, Room 3128, Building 37, Bethesda, MD 20892, United States.
Jianfei
J
Zhao
Laboratory of Metabolism, National Cancer Institute, National Institutes of Health, Room 3128, Building 37, Bethesda, MD 20892, United States.
Ishminder K
IK
Mann
Laboratory of Metabolism, National Cancer Institute, National Institutes of Health, Room 3128, Building 37, Bethesda, MD 20892, United States.
Syed K
SK
Sayeed
Laboratory of Metabolism, National Cancer Institute, National Institutes of Health, Room 3128, Building 37, Bethesda, MD 20892, United States.
Ajeet
A
Mandal
Department of Biochemistry, North Carolina State University, 128 Polk Hall, Raleigh, NC 27695, United States.
Robert B
RB
Rose
Laboratory of Metabolism, National Cancer Institute, National Institutes of Health, Room 3128, Building 37, Bethesda, MD 20892, United States. Electronic address: vinsonc@mail.nih.gov.
Charles
C
Vinson
D044503:5-Methylcytosine / Q000737:chemistry / Q000378:metabolism; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D051792:Basic Helix-Loop-Helix Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D002942:Circular Dichroism; D003596:Cytosine / Q000031:analogs & derivatives* / Q000737:chemistry / Q000378:metabolism; D015226:Dinucleoside Phosphates / Q000737:chemistry / Q000378:metabolism; D024721:E-Box Elements; D006801:Humans; D008958:Models, Molecular; D008969:Molecular Sequence Data; D011485:Protein Binding; D055503:Protein Multimerization
D044503:5-Methylcytosine; D051792:Basic Helix-Loop-Helix Proteins; D003596:Cytosine; D015226:Dinucleoside Phosphates; C560974:5-carboxylcytosine; C015772:CpG dinucleotide
Basic-helix-loop-helix; CG dinucleotide; Carboxylation; DNA binding; E-Box motif; Tcf3|Ascl1 heterodimer