Intracellular and Plasma Membrane Events in Cholesterol Transport and Homeostasis

Figure 2

Protein-protein interactions involved in cholesterol efflux by cholesterol transporters. Data for human ABCA1 (a), ABCG1 (b), and SR-B1 (SCARB1) (c) molecules were imported from STRING database with Cytoscape STRING plugin. Confidence cutoff for interactions was chosen as 0.95, 0.7, and 0.8, respectively. (a) apoA-I is the major protein component of HDL; PPARA is a nuclear receptor, transcription factor, key regulator of lipid metabolism; NR1H2 is an oxysterols receptor LXR-beta–nuclear receptor that regulates cholesterol uptake; NR1H3 is an oxysterols receptor LXR-alpha-nuclear receptor that regulates homeostasis and cholesterol uptake. (b) NR1H3 and NR1H2 are mentioned above; MATK is a megakaryocyte-associated tyrosine-protein kinase that could play a significant role in the signal transduction of hematopoietic cells. PCP4 is a Purkinje cell protein 4 that plays an important role in synaptic plasticity, regulating calmodulin function; ABCG2 is an urate exporter that is able to mediate the export of protoporhyrin IX and implicated in the efflux of numerous drugs and xenobiotics; apoE is an apolipoprotein that mediates the binding, internalization, and catabolism of lipoprotein particles; SR-B1 (SCARB1) is a receptor for different ligands, receptor for HDL. (c) apoA-I and apoE are mentioned above; ABCA1 and ABCG1 play a role in HDL metabolism; apoB is a major protein component of chylomicrons, VLDL, and LDL; PPARG is a nuclear receptor that controls the peroxisomal beta-oxidation pathway of fatty acids and regulates adipocyte differentiation and glucose homeostasis; PDZK1 is a PDZ domain containing scaffolding protein; THBS1 is a thrombospondin-1, adhesive glycoprotein, that mediates cell-to-cell and cell-to-matrix interactions, binds heparin.

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(b)

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