1r- Hydrophobic signals and control of transcription Flashcards
What is a special feature of hydrophobic signalling molecules?
They can diffuse through the phospholipid bilayers of membranes, and then bind to intracellular receptors
What are the receptors for hydrophobic signalling molecules?
Transcription factors
What are transcription factors?
Proteins that when bound to DNA can either stimulate or inhibit initiation of transcription
What are two examples of hydrophobic signalling molecules?
The steroid hormones oestrogen and testosterone
Where do steroid hormone bind to specific receptors?
In the cytosol or the nucleus
What does the hormone-receptor complex do?
Moves to the nucleus where it binds to specific sites on DNA and affects gene expression
What does the hormone-receptor complex bind to?
Specific DNA sequences called hormone response elements (HREs)
What does binding at the of hormone-receptor complexes at HREs influence?
The rate of transcription, with each steroid hormone affecting the gene expression of many different genes
