FMBG 12 Signal Transduction Coupled Tx Factors Flashcards Preview

Genetics > FMBG 12 Signal Transduction Coupled Tx Factors > Flashcards

Flashcards in FMBG 12 Signal Transduction Coupled Tx Factors Deck (18)
Loading flashcards...
0
Q

Extracellular signals that regulate transcription factor activity must regulate:

A

a. nuclear localization, and/or b. DNA binding, and/or c. transactivation

1
Q

Describe the ribosomes that synthesize transcription factors (location, solubility)

A

Free ribosomes, soluble

2
Q

How many nuclear pore complexes per cell?

A

3000-4000 NPCs in average cell

3
Q

of Macromolecules transferred per second in a cell through nuclear pores

A

500 per sec

4
Q

What size molecules require active transport into nucleus?

A

>60,000 daltons

5
Q

Do proteins destined for the nucleus possess?

A

Nuclear localization signals

6
Q

Describe a nuclear localization signal (size, # of amino acids)

A

~5 amino acids long, usually contains Lys and Arg

7
Q

Different nuclear localization signals are recognized by families of ___________

A

Nuclear import receptors

8
Q

Gating of nuclear transport is mediated by: a) Ras b) Rho c) Ran d) Rab

A

c) Ran

9
Q

Ran most closely resembles what other G protein we learned about in detail?

A

Ras

10
Q

A key distinction between ran and ras?

A

Ran is compartmentalized across the nuclear membrane

11
Q

Binding of Ran-GTP to the cargo-import receptor complex causes ______. This happens in the ______.

A

cargo release (in the nucleus)

12
Q

Cytosol vs nucleus: Which most likely has a higher conc of GEF?

A

Nucleus

13
Q

We regulate access to nucleus by regulating access to the ________

A

Nuclear localization signal

14
Q

Current model of nuclear pore: a) Selective phase b) Oily spaghetti c) Brownian affinity gate

A

b) oily spaghetti

15
Q

T/F: membrane proteins from the ER require a highly specialized process for nuclear import compared to soluble protein

A

False - membrane and soluble proteins are generally imported the same way, and both have nuclear localization signals.

16
Q

What happens when CREB binds to DNA?

A

Depends on whether the CREB has been phosphorylated by activated PKA. Phosphorylated CREB has an activated transactivation domain that recruits CREB-binding protein (CBP). Inactive CREB binds to DNA, but does nothing.

17
Q

Simplest description of “activation of transactivation”

A

Phosphorylation of a protein leads to binds to other transcription factors.