2.2 - Signal Transduction

Question 1

major chemical groups of hormones

Answer 1

• hormones derived from fatty acids
• steroid hormones
• amino acid derivatives
• peptide hormones

Question 2

Examples of hormones that bind to nuclear receptors

Answer 2

• cortisol
• retinoic acid
• thyroxine

Question 3

general design of transcription factors in the nuclear-receptor superfamily

Answer 3

• Variable Region
• DNA-binding domain – lots of homology; contains two copies of the C4 zinc finger motif
• Ligand-binding domain

Question 4

experiment demonstrating glucocorticoid receptor (GR) mediates translocation to the nucleus in the presence of hormone

Answer 4

• Beta-galactosidase only – enzyme was localized to the cytoplasm in the presence and absence of the glucocorticoid hormone Dex
• fusion protein of Beta-galactosidase and glucocorticoid receptor – fusion protein was present in the cytoplasm in the absence of hormone, but was transported to the nucleus in the presence of hormone
• Beta-galactosidase + GR ligand-binding domain – exhibited hormoned dependent transport of the function protein to the nucleus