ABCA1 Expression is Down-Regulated by SREBP microRNA

The ABCA1 (ATP-binding cassette transporter-A1) gene encodes a transmembrane protein, which plays a major role in phospholipid homeostasis by regulating cholesterol efflux from the cell. ABCA1 antibody studies have shown ABCA1 expression is up/down regulated by the transcription factors LXR and SREBP2 respectively. Now, new evidence points to microRNA (mRNA) being integral to SREBP2 down-regulation of ABCA1. We at Novus Biologicals have a large number of LXR, SREBP2 and ABCA1 antibody products in our antibody catalog.

ABCA1 is expressed on the Golgi body and plasma membrane. Expression is regulated by transcription factors in response to alterations in the cholesterol flux. Its role is to mediate transport of lipids between the two expression sites, and to moderate cholesterol and phospholipid efflux to the ApoA1 and ApoE apolipoproteins, for HDL (high-density lipoprotein) formation. The protein is expressed in high levels in the liver, gut and adipose tissue.

SREBP-2 (sterol-regulatory-element-binding protein 2) controls cholesterol homeostasis by upregulation of genes involved in cholesterol synthesis and uptake, e.g. HMG-CoA, while LXR upregulates expression of ABCA1 and other cholesterol efflux genes. Oxysterols (cholesterol derivatives) inhibit SREBP2 activation whilst acting as LXR ligands. ABCA1 antibody studies conducted by J.Wang have suggested SREBP2 controls ABCA1 expression by maintaining a supply of oxysterol ligands for LXR.

Recently, miRNAs have been shown to play an important role in cholesterol homeostasis by post-transcriptional regulation of a number of lipid metabolism genes, with ABCA1 antibody studies demonstrating ABCA1 inhibition by miRNA action. A study conducted in 2010 showed inhibition was achieved by two miRNAs embedded in the SREBP2 host gene. This exciting development has opened new avenues of research for our antibody catalog.

Novus Biologicals offers many ABCA1 reagents for your research needs including:

• ABCA1 Antibodies
• ABCA1 RNAi
• ABCA1 Peptides and Proteins