Step I Steroid Hormone MOA

[lemonade90]

I was doing some Qs in the FA Q book and came to a question asking:

Which of the following steps in the steroid hormone mech is the last step necessary before DNA binding within the nucleus?

I narrowed it down to two choices and picked the first one (the answer was the latter)
-Hormone binding to DNA enhancer
-Transformation of the hormone receptor complex

The relevant portion of the explanation says:

Steroid hormons..."bind to an intracellular receptor either in the cyoplasm or within the nucleus. The hormone receptor complex must transform in order to reveal the hormone's DNA bindng domain; without this step, it is unable to carry out its action. ONce the binding domain is revealed, the hormone binds the DNA enhancer element and generates gene transcription"

I am a bit confused by the answer as I thought that steroids bind to their receptors. This complex then transforms. The transformed complex then binds to the HRE (the last step).

Why is my thinking incorrect?😕

 

[HelpPleaseMD]

http://highered.mcgraw-hill.com/sit...anism_of_steroid_hormone_action__quiz_1_.html

From what I understand, the hormone must be bound by a receptor before any action can occur.

 

[lemonade90]

http://highered.mcgraw-hill.com/sit...anism_of_steroid_hormone_action__quiz_1_.html

From what I understand, the hormone must be bound by a receptor before any action can occur.

Okay, yes. Just the bolded part was worded akward for me.