1 - Steroid Hormones General

Question 1

3 Sex Steroid Families Essential for Reproduction

Answer 1

1) Estrogens
2) Progesterone
3) Androgens

Question 2

What is the function of Estrogens?

Answer 2

Development and maintenance of female characteristics

Question 3

What is the function of Progesterones / Progestins?

Answer 3

Preparation for / maintenance of pregnancy

Question 4

What are the functions of Androgens?

Answer 4

Development and maintenance of male characteristics

Question 5

What is the function of aromatase?

Answer 5

Convert androgens to estrogens.

Converts testosterone into 17Beta-Estradiol

Question 6

What feature of oestrogen is different to testosterone?

Answer 6

Contains an aromatic ring - only family to do so.

Question 7

What is the name of the process to produce mRNA?

Answer 7

Transcription

Question 8

What is the name of the process to produce protein?

Answer 8

Translation

Question 9

What are the 4 Steroid Receptor subsets?

Answer 9

Androgen receptor (AR)
Estrogen receptor (ER)
Progesterone receptor (PR)
Glucocorticoid receptor (GR)

Question 10

What is the role of steroid receptors?

Answer 10

Mediate the effects of hormonal ligands but influencing the transcription of target genes

Question 11

Where do steroid hormones bind on DNA?

Answer 11

Steroid response element (SRE)

Question 12

What are the 3 domains that make up the general nuclear-receptor structure from N-terminal to C-terminal?

Answer 12

1) A promoter-activating domain (for target genes)
2) The zinc-finger domain needed for DNA binding (to the response element)
3) The hormone-binding domain (also binds to second unit of the dimer)

Question 13

What is the SRE?

Answer 13

Short sequence of DNA found within the promoter region that enables steroid hormone-receptor complex to bind.

Question 14

Describe the process of Steroid-Hormone Receptors Regulating Gene Transcription

Answer 14

• Hormone binds to receptor
• Complex binds to second copy of itself to form homodimer
• Move from cytosol (if necessary) into nucleus
• Bind to SRE
• Modulates transcription
• Bind to other protein cofactors

Question 15

What is the function of Zinc-finger domains (+ number of zinc atoms)

Answer 15

Binding to DNA

4

Question 16

List one positive and one negative SRE response elements using cortisol as an example

Answer 16

POSITIVE:
- Binding to SRE of genes needed for gluconeogenesis

NEGATIVE:
- Binding to SRE of insulin receptor gene, diminishing their expression (occurring in the Beta-cells of the pancreas)

Question 17

Name 1 factor that determines whether a steroid hormone will have an effect in a given cell

Answer 17

Presence of steroid hormone receptor.

Every cell has all the available SREs, however, it requires its receptor for it to have an effect

Question 18

How are steroids carried within the blood? And do they enter with the carrier protein?

Answer 18

Bound to a carrier protein

No.

Question 19

What does secondary transcription regulation refer to?

Answer 19

Following a primary response that occurs following steroid-receptor binding to SRE.

Secondary transcription factors can further activate / repress downstream target genes.