ABCA1

Jamshed Arslan, Pharm D, PhD

By Jamshed Arslan Pharm.D., PhD.

Niemann-Pick type C1 (NPC1) mediates low-density cholesterol transport from late endosomes and lysosomes to other areas of the cell via receptor mediation endocytosis.  Although cholesterol moves freely inside the cell, it cannot independently export out of the lysosome, which is where NPC1 steps in.

The ABCA1 molecule is a primary gatekeeper for regulating the intracellular transport of cholesterol. It belongs to a larger related multifamily of cAMP-dependent anion transporter cell membrane molecules. These key proteins are responsible for trafficking the reverse efflux of cholesterol from cells into peripheral tissues using the apolipoprotein A-1 (apo) carrier. In particular, the ABCA1 molecule exhibits a diverse expression profile and is found most highly expressed in macrophages.

The ATP-binding cassette transporter A1 (ABCA1) protein is a key gatekeeper for regulating intracellular cholesterol transport. It is one member of a large family of genes comprised of cAMP-dependent anion transporter cell membrane proteins. These important proteins regulate reverse cholesterol efflux from cells into the peripheral tissues via apolipoprotein A-1 (apo). ABCA1 in particular has a diverse expression profile and is most highly expressed in macrophages.

The ATP-binding cassette (ABC) transporter genes are key gatekeeper molecules that regulate the amount of dietary cholesterol retained by the body. They are a multifamily comprised of cAMP-dependent anion transporter cell membrane proteins that monitor reverse cholesterol efflux from cells into the peripheral tissues via apolipoprotein A-I (Apo). ABCG8 is expressed at high levels in the liver and intestine.

ABCA1 is a key gatekeeper influencing intracellular cholesterol transport, and is an important member of a multifamily of cAMP-dependent anion transporter cell membrane proteins that regulate reverse cholesterol efflux from cells in peripheral tissues to apolipoprotein A1. ABCA1 has a wide expression profile with highest expression levels found in macrophages.

SREBP1 (sterol-regulatory-element-binding protein 2) is a basic-helix-loop-helix-leucine zipper (bHLH-ZIP) transcription factor. It regulates sterol and cholesterol homeostasis by controlling enzymes involved in cholesterol synthesis and uptake, e.g. HMG-CoA. The SREBP1 antibody was used in fundamental studies to dissect SREBP1 domains and downstream signaling (1).

Sterol-regulatory-element-binding protein 2 (SREBP2) is a transcription factor that regulates cholesterol homeostasis by controlling enzymes involved in cholesterol synthesis and uptake, e.g. HMG-CoA.

LXR Alpha, also known as Liver X receptor Alpha is a 50KDa protein that belongs to the nuclear hormone receptor family located in the nucleus. It is specifically expressed in the liver, kidney and intestine; however it has also been found in the spleen, macrophages and the adrenals. All of these tissues play an important role in lipid metabolism. The primary role of LXR Alpha is to maintain cholesterol homeostasis in macrophages by regulating the genes involved in this.