The progesterone receptor (PR) is a steroid hormone receptor and transcription factor. The protein SRC-1, which does not bind DNA by itself, can bind to PR and increase expression of genes regulated by PR. Based on this information, SRC-1 is best described as a(n)

Question

A.  coactivator.
B.  inducer.
C.  general transcription factor.
D.  specific transcription factor.

Clarify Question
· What is the key concept addressed by the question?
· What type of thinking is required?
· What key words does the question contain and what do they mean?

Gather Content
· What do you already know about coactivators?

Consider Possibilities
· Consider the different answer options. Which can you rule out?

Choose Answer
· Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?
 Reflect on Process
· Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?

Answer 1

A.  coactivator.

Clarify Question
· What is the key concept addressed by the question?
        o This question addresses coactivators.
· What type of thinking is required?
        o This question is asking you to take what you already know and apply it to this unfamiliar situation.
· What key words does the question contain and what do they mean?
        o A steroid hormone receptor is a special kind of specific transcription factor. They respond to hormones, then enter the nucleus and regulate transcription.

Gather Content
· What do you already know about coactivators?
        o In our text, coactivators are described as transcription factors that stabilize the transcription complex by bridging activator proteins with the complex. They act by binding the transcription factor and then binding to another part of the transcription apparatus.

Consider Possibilities
· Consider the different answer options. Which can you rule out?
        o Is SRC-1 best described as a general transcription factor? No, because it does not act in the transcription of every gene.
        o Is SRC-1 best described as an inducer? No. Our text gave us several examples of inducers. All of them were small molecules in prokaryotes that activate genes by inhibiting the binding of a repressor protein.
        o Is SRC-1 best described as a specific transcription factor? Perhaps – but its role is to enhance the stimulation by another specific transcription factor, the progesterone receptor.

Choose Answer
· Given what you now know, what information and/or problem solving approach is most likely to produce the correct answer?
        o SRC-1 is best described as a coactivator – a protein that acts to enhance the of other specific transcription factors, by bridging activator proteins with the complex.
 Reflect on Process
· Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?
        o This question asked what is the best description of the protein SRC-1.
        o The question required you to take what you already know and apply it to this unfamiliar situation.
        o Did you recognize that as a “helper” for another specific transcription factor, SRC-1 isbest described as a coactivator?