?

Biochemistry

Free Version

Upgrade subject to access all content

Difficult

LXR-RXR Dimers: Regulatory Control of Gene Transcription

BIOCHM-D1WL8R

The Liver X Receptor (LXR) and Retinoid X Receptor (RXR) form a dimer together which binds to DNA. Each also has others binding sites specific for other molecules (and each other).

The LXR-RXR dimer regulates expression of host of genes including many involved in cholesterol transport, including ABC transporters, GLUT4, Apoproteins C1, C2, D, and E and Acetyl-CoA carboxylase. When inactivated, normally a corepressor molecule is bound to each LXR and RXR.

Which of the following is NOT typically bound to either LXR or RXR when the dimer is activating transcription of genes?

A

Cholesterol or oxysterol.

B

Co-activator(s).

C

DNA.

D

IRF-3 (interferon regulatory transcription factor).

E

9-cis-retinoic acid.