Gene transcriptions/Elements/Metal responsives

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Metal responsive elements (MRE)s, or TGC boxes, may occur in the core promoter of some human DNA genes.

TGC boxes[edit | edit source]

Notation: let the symbol MT stand for metallothionein.

"The metallothionein (MT) genes provide a good example of eucaryotic promoter architecture. MT genes specify the synthesis of low-molecular-weight metal-binding proteins. They are transcriptionally regulated by the metal ions cadmium and zinc (11), glucocorticoid hormones (18), interferon (14), interleukin-1 (22), and tumor promoters (2). The metal ion regulation of MTs is conferred by a short sequence element called the metal-responsive element (MRE [21]) or TGC box (31, 34), which functions as a metal ion-dependent enhancer."[1]

Consensus sequences[edit | edit source]

"The promoter regulatory sequences are identified by homology to published GRE (21), MRE (35), and GC box (15) consensus sequences."[1]

Here "is a consensus sequence for the MREs of the rat MT-1 gene."[1] In the direction of transcription on the DNA template strand: 3'-CNNTGCRCYCGGGNC-5', where R = purine; Y = pyrimidine; and N = any nucleotide (nt).[1]

"[T]hree potential metal response elements (MREs) [overlap] the E-boxes in the repeats, (TGCACGT with TGCRCNC being the consensus sequence; 17,18)."[2]

The reproducible consensus sequence seems to be 3'-TGCRCNC-5', specifically 3'-TGC(A/G)CNC-5'.

MREs[edit | edit source]

Six MREs lie in the proximal promoter of the rat MT-1 gene upstream of the TATA box to almost -200 nts from the transcription start site.[1]

Hypotheses[edit | edit source]

  1. At least two human gene isoforms have their transcription initiated by an MRE.

See also[edit | edit source]

References[edit | edit source]

  1. 1.0 1.1 1.2 1.3 1.4 Robert D. Andersen, Susan J. Taplitz, Sandy Wong, Greg Bristol, Bill Larkin, and Harvey R. Herschman (October 1987). "Metal-Dependent Binding of a Factor In Vivo to the Metal-Responsive Elements of the Metallothionein 1 Gene Promoter". Molecular and Cellular Biology 7 (10): 3574-81. doi:10.1128/​MCB.7.10.3574. Retrieved 2013-04-15. 
  2. Barbara Levinson, Rebecca Conant, Rhonda Schnur, Soma Das, Seymour Packman and Jane Gitschier (1996). "A Repeated Element in the Regulatory Region of the MNK Gene and Its Deletion in A Patient With Occipital Horn Syndrome". Human Molecular Genetics 5 (11): 1737-42. doi:10.1093/hmg/5.11.1737. Retrieved 2013-04-15. 

Further reading[edit | edit source]

External links[edit | edit source]