+ Site Statistics
+ Search Articles
+ PDF Full Text Service
How our service works
Request PDF Full Text
+ Follow Us
Follow on Facebook
Follow on Twitter
Follow on LinkedIn
+ Subscribe to Site Feeds
Most Shared
PDF Full Text
+ Translate
+ Recently Requested

A nuclease hypersensitive element in the human c-myc promoter adopts several distinct i-tetraplex structures

A nuclease hypersensitive element in the human c-myc promoter adopts several distinct i-tetraplex structures

Biochemical and Biophysical Research Communications 278(1): 158-166

Nucleic acid structure-function correlations are pivotal to major biological events like transcription, replication, and recombination. Depending on intracellular conditions in vivo and buffer composition in vitro, DNA appears capable of inexhaustible structure variation. At moderately acidic, or even neutral pH, DNA strands that are rich in cytosine bases can associate both inter- and intramolecularly to form i-tetraplexes. The hemiprotonated cytosine(+)-cytosine base pair constitutes the building block for the formation of i-tetraplexes, and motifs for their formation are frequent in vertebrate genomes. A major control element upstream of the human c-myc gene, which has been shown to interact sequence specifically with several transcription factors, becomes hypersensitive to nucleases upon c-myc expression. The control element is asymmetric inasmuch as that one strand is uncommonly rich in cytosines and exhibits multiple motifs for the formation of i-tetraplexes. To investigate the propensity for their formation we employ circular dichroism (CD) in combination with ultra violet (UV) spectroscopy and native gel electrophoresis. Our results demonstrate the cooperative formation of well-defined i-tetraplex structures. We conclude that i-tetraplex formation occurs in the promoter region of the human c-myc gene in vitro, and discuss implications of possible biological roles for i-tetraplex structures in vivo. Hypothetical formation of intramolecular fold-back i-tetraplexes is important to c-myc transcription, whereas chromosomal translocation events might involve the formation of bimolecular i-tetraplex structures.

Please choose payment method:

(PDF emailed within 0-6 h: $19.90)

Accession: 010084582

Download citation: RISBibTeXText

PMID: 11071868

DOI: 10.1006/bbrc.2000.3783

Related references

Thermodynamics of i-tetraplex formation in the nuclease hypersensitive element of human c-myc promoter. Biochemical and Biophysical Research Communications 320(4): 1220-1227, 2004

A nuclease-hypersensitive element of the human c-myc promoter interacts with a transcription initiation factor. Molecular and Cellular Biology 9(11): 5123-5133, 1989

PuF/NM23-H2/NDPK-B transactivates a human c-myc promoter-CAT gene via a functional nuclease hypersensitive element. Oncogene 10(12): 2343-2347, 1995

The 3'-end region of the human PDGFR-β core promoter nuclease hypersensitive element forms a mixture of two unique end-insertion G-quadruplexes. Biochimica et Biophysica Acta. General Subjects 1862(4): 846-854, 2018

Quadruplex-duplex competition in the nuclease hypersensitive element of human c-myc promoter: C to T mutation in C-rich strand enhances duplex association. Biochemical and Biophysical Research Communications 327(1): 49-56, 2005

The mouse mammary tumor virus promoter adopts distinct chromatin structures in human breast cancer cells with and without glucocorticoid receptor. Journal of Biological Chemistry 275(26): 20061-8, 2000

Characterization of the G-quadruplexes in the duplex nuclease hypersensitive element of the PDGF-A promoter and modulation of PDGF-A promoter activity by TMPyP4. Nucleic Acids Research 35(22): 7698-7713, 2007

The Consequences of Overlapping G-Quadruplexes and i-Motifs in the Platelet-Derived Growth Factor Receptor β Core Promoter Nuclease Hypersensitive Element Can Explain the Unexpected Effects of Mutations and Provide Opportunities for Selective Targeting of Both Structures by Small Molecules To Downregulate Gene Expression. Journal of the American Chemical Society 139(22): 7456-7475, 2017

Metastases suppressor NM23-H2 interaction with G-quadruplex DNA within c-MYC promoter nuclease hypersensitive element induces c-MYC expression. Nucleic Acids Research 37(1): 172-183, 2009

Binding of THZif-1, a MAZ-like zinc finger protein to the nuclease-hypersensitive element in the promoter region of the c-MYC protooncogene. Journal of Biological Chemistry 271(49): 31322-31333, 1996

Thermodynamic stability and folding kinetics of the major G-quadruplex and its loop isomers formed in the nuclease hypersensitive element in the human c-Myc promoter: effect of loops and flanking segments on the stability of parallel-stranded intramolecular G-quadruplexes. Biochemistry 49(43): 9152-9160, 2010

Salicylic acid and the hypersensitive response initiate distinct signal transduction pathways in tobacco that converge on the as-1-like element of the PR-1a promoter. European Journal of Biochemistry 270(24): 4876-4886, 2003

A transcriptional regulatory element is associated with a nuclease-hypersensitive site in the pol gene of human immunodeficiency virus type 1. Journal of Virology 68(4): 2632-2648, 1994

Spontaneous DNA lesions modulate DNA structural transitions occurring at nuclease hypersensitive element III(1) of the human c-myc proto-oncogene. Biochemistry 51(26): 5257-5268, 2012

The promoter-proximal KCS element of the PKR kinase gene enhances transcription irrespective of orientation and position relative to the ISRE element and is functionally distinct from the KCS-like element of the ADAR deaminase Promoter. Journal of Interferon and Cytokine Research 22(8): 891-898, 2002