Interactions of RXRa with nutrients

Abstract

<p>Under healthy conditions, there has to exist a balance between lipid and sugar uptake and metabolism. Several nuclear receptors, proteins that recognize specific molecules and regulate expression of genes involved in many of the body's processes, are thought to be responsible for maintaining this balance. In liver, PPARa has the role to regulate metabolic pathways by detecting lipids. Knowing that PPARa also binds glucose, in the presence of high glucose, PPARa's ability to bind with lipids is altered such that a competition exists between lipids and sugars. The PPARa works by partnering with other nuclear receptors (Retinoid X Receptor alpha, RXRa or Liver X Receptor alpha, LXRa). Since glucose has already been found to bind with LXRa, we want to see if RXRa would also bind glucose or other sugars. In order to accomplish this goal we needed to purify RXRa protein. This was done using a bacterial expression plasmid with a histidine and GST tag. This plasmid was transformed into the Rosetta BL21 strain of E. coli. Several growth and induction conditions were tested. Protein was purified with metal affinity chromatography using the histidine tag. Protein purity was examined by SDS-PAGE with Coomassie Blue Stain and Western Blot. This purified protein was then used to examine RXRa's ability to bind with sugar. These results could be important since nuclear receptors regulate a lot of genes. The molecules that bind with them (leading to nuclear receptor activation or repression) may strongly affect our health and inappropriate levels may lead to disease.</p><p>This presentation occurred at the Wright State University Campus-Wide Celebration of Research, Scholarship and Creative Activities on April 16, 2010</p>