Cytosine methylation does not affect binding of transcription factor Sp1

Journal Article · Fri Apr 01 00:00:00 EST 1988 · Proceedings of the National Academy of Sciences of the United States of America; (USA)

DOI:https://doi.org/10.1073/pnas.85.7.2066· OSTI ID:6897513

Harrington, M A; Jones, P A ^[1]; Imagawa, M; Karin, M ^[2]

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1. Univ. of Southern California School of Medicine, Los Angeles (USA)
2. Univ. of California, San Diego, La Jolla (USA)

DNA methylation may be a component of a multilevel control mechanism that regulates eukaryotic gene expression. The authors used synthetic oligonucleotides to investigate the effect of cytosine methylation on the binding of the transcription factor Sp1 to its target sequence (a G+C-rich sequence known as a GC box). Concatemers of double-stranded 14-mers containing a GC box successfully competed with the human metallothionein IIA promoter for binding to Sp1 in DNase I protection experiments. The presence of 5-methylcytosine in the CpG sequence of the GC box did not influence Sp1 binding. The result was confirmed using double-stranded 20-mers containing 16 base pairs of complementary sequence. Electrophoretic gel retardation analysis of annealed 28-mers containing a GC box incubated with an Sp1-containing HeLa cell nuclear extract demonstrated the formation of DNA-protein complexes; formation of these complexes was not inhibited when an oligomer without a GC box was used as a competitor. Once again, the presence of a 5-methylcytosine residue in the GC box did not influence the binding of the protein to DNA. The results therefore preclude a direct effect of cytosine methylation on Sp1-DNA interactions.

• OSTI ID: 6897513
• Journal Information: Proceedings of the National Academy of Sciences of the United States of America; (USA), Vol. 85:7; ISSN 0027-8424
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
CYTOSINE
METHYLATION
GENE REPRESSORS
DNA SEQUENCING
METALLOTHIONEIN
GENE REGULATION
ATP
DNA-ASE
ELECTROPHORESIS
HELA CELLS
PHOSPHORUS 32
TRANSCRIPTION
AMINES
AZINES
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
CHEMICAL REACTIONS
DAYS LIVING RADIOISOTOPES
ENZYMES
ESTERASES
HETEROCYCLIC COMPOUNDS
HYDROLASES
ISOTOPES
LIGHT NUCLEI
METALLOPROTEINS
NUCLEI
NUCLEOPROTEINS
NUCLEOTIDES
ODD-ODD NUCLEI
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANIC OXYGEN COMPOUNDS
PHOSPHODIESTERASES
PHOSPHORUS ISOTOPES
PROTEINS
PYRIMIDINES
RADIOISOTOPES
STRUCTURAL CHEMICAL ANALYSIS
550201* - Biochemistry- Tracer Techniques