Oestrogen and glucocorticoid responsive elements are closely related but distinct

Area of Science:

• Molecular biology
• Genetics
• Endocrinology

Background:

• Glucocorticoid receptors bind DNA at specific sequences called glucocorticoid-responsive elements, which stimulate transcription.
• A 15-base pair oligonucleotide with symmetry is crucial for glucocorticoid induction and is also recognized by the progesterone receptor.

Purpose of the Study:

• To define a palindromic DNA sequence that confers estrogen inducibility.
• To investigate the relationship between estrogen-responsive elements and glucocorticoid-responsive elements.

Main Methods:

• Defined a 15-base pair palindromic sequence based on conserved elements in vitellogenin genes.
• Tested the ability of this sequence to confer estrogen inducibility on a heterologous promoter.
• Modified the sequence by single or double base substitutions to assess glucocorticoid responsiveness.

Main Results:

• The defined palindromic sequence conferred estrogen inducibility on a heterologous promoter.
• Substitution of one or two bases converted the estrogen-responsive element into a glucocorticoid-responsive element.
• Demonstrated that steroid-responsive elements form a family of related DNA sequences.

Conclusions:

• Steroid receptors recognize related DNA sequences, forming a family of steroid-responsive elements.
• The DNA-binding domains of steroid receptors are closely related, supporting the concept of a shared recognition motif.