Social Cells 4: Nuclear Receptors

Question 1

What are nuclear receptors the primary receptors for?

Answer 1

Hormones and vitamins

Question 2

How are nuclear receptors usually classified?

Answer 2

By their structural features or their mechanism of action

Question 3

NR binding DNA as
homodimers

Answer 3

Two copies of the same receptor that bind together then bind to DNA

Question 4

What are some examples of homodimers?

Answer 4

Glucocorticoids, Progesterone, Oesotrogen

Question 5

NR binding the DNA as
heterodimers

Answer 5

One copy of the receptor binds with retinoid receptor x to form a heterodimer

Question 6

Type 1 NR

Answer 6

Homodimers, bind to their ligands in the cytoplasm then move into the nucleus to bind to DNA

Question 7

Type 2 NR

Answer 7

Already found in the nucleus, ligand has to penetrate nuclear membrane

Question 8

What happens to homodimers once they enter the nucleus

Answer 8

With the help of coactivators and RNA polymerase they bind to the DNA to regulate transcription

Question 9

How may hormones enter the nucleus?

Answer 9

Through Nuclear Pores

Question 10

Corepressors

Answer 10

Mediate repression of nuclear receptors

Question 11

Autologous

Answer 11

The concentration of the receptor can increase or decrease upon their activation (examples of positive feedback)

Question 12

Heterologous

Answer 12

The concentration of the receptor can increase or decrease upon the activation of other nuclear receptors