ATP binding cassette

Currently, five different molecular classes of mdr efflux pumps are known [5], While pumps of the the ATP-binding cassette (ABC) transporter superfamily are driven by ATP hydrolysis, the other four superfamilies called resistance-nodulation-division (RND), major facilitator superfamily (MFS), multidrug and toxic compound extrusion (MATE), and small multidrag resistance transporter (SMR) are driven by the proton-motive force across the cytoplasmic membrane. Usually a single pump protein is located within the cytoplasmic membrane. However, the RND-type pumps which are restricted to Gram-negative bacteria consist of two additional components, a periplasmic membrane fusion protein (MFP) which connects the efflux pump to an outer... 

SURs are members of the ATP-binding cassette (ABC) family of proteins ( ABC transporters) with a typical ABC core consisting of two bundles of six... 

ATP-binding cassette (ABC) transporters are efflux pumps that derive the energy needed for drug extrusion from the hydrolysis of ATP. Bacterial ABC antibiotic efflux transporter encoded on plasmids is a significant... 

Jessup W, Gelissen IC, Gaus K, Kritharides L (2006) Roles of ATP binding cassette transporters Al and Gl, scavenger receptor BI and membrane lipid domains in cholesterol export from macrophages. Curr Opin Lipidol 17(3) 247-57... 

Figure 25-5. Metabolism of high-density lipoprotein (HDL) in reverse cholesteroi transport. (LCAT, lecithinxholesterol acyltransferase C, cholesterol CE, cholesteryl ester PL, phospholipid A-l, apolipoprotein A-l SR-Bl, scavenger receptor B1 ABC-1, ATP binding cassette transporter 1.) Prep-HDL, HDLj, HDL3—see Table 25-1. Surplus surface constituents from the action of lipoprotein lipase on chylomicrons and VLDL are another source of preP-HDL. Hepatic lipase activity is increased by androgens and decreased by estrogens, which may account for higher concentrations of plasma HDLj in women.

Moreover, efficient rhodopsin regeneration may precede enzymatic reduction of all-fran.v-retinal to all-trans-retinol in the aged retina (Figure 15.2c) (Schadel et al., 2003). Upon rhodopsin regeneration, all-trans-retinal is released from the exit site of the protein into the lipid membrane (Figure 15.2c) (Schadel et al., 2003). From here the removal of all-tnms-retinal to the outer leaflet of the disc membrane is dependent on activity of ATP-binding cassette trasporter A4 (ABCA4) present in the rim of photoreceptor disc, known also as ABCR protein. 

Intracellular transport and efflux from cells of lipophilic molecules can be mediated by several members of the ATP-binding cassette (ABC) transporters family, some of which have been identified in the brain, including the retina (Kim et al., 2008 Sarkadi et al., 2006). 

Chen, W, Sun, Y, Welch, C, Gorelik, A, Leventhal, AR, Tabas, I, and Tall, AR, 2001. Preferential ATP-binding cassette transporter A1-mediated cholesterol efflux from late endosomes/lysosomes. J Biol Chem 276, 43564-43569. 

Faulkner, LE, Panagotopulos, SE, Johnson, JD, Woollett, LA, Hui, DY, Witting, SR, Maiorano, JN, and Davidson, WS, 2008. An analysis of the role of a retroendocytosis pathway in ATP-binding cassette transporter (ABCA1)—Mediated cholesterol efflux from macrophages. J Lipid Res, M800048-JLR800200. 

Kim, WS, Weickert, CS, and Gamer, B, 2008. Role of ATP-binding cassette transporters in brain lipid transport and neurological disease. JNeurochem 104, 1145-1166. 

Koldamova, RP, Lefterov, IM, Ikonomovic, MD, Skoko, J, Lefterov, PI, Isanski, BA, DeKosky, ST, and Lazo, JS, 2003. 22R-hydroxycholesterol and 9-cw-retinoic acid induce ATP-binding cassette transporter A1 expression and cholesterol efflux in brain cells and decrease amyloid beta secretion. J Biol Chem 278, 13244-13256. 

Lorenzi, I, von Eckardstein, A, Cavelier, C, Radosavljevic, S, and Rohrer, L, 2008. Apolipoprotein A-I but not high-density lipoproteins are internalised by RAW macrophages Roles of ATP-binding cassette transporter A1 and scavenger receptor BI. JMolMed 86, 171-183. 

Beta-cryptoxanthin, a novel natural RAR ligand, induces ATP-binding cassette transporters in macrophages. Biochem Pharmacol 74, 256-264. 

Von Eckardstein, A, Langer, C, Engel, T, Schaukal, I, Cignarella, A, Reinhardt, J, Lorkowski, S, Li, Z, Zhou, X, Cullen, P, and Assmann, G, 2001. ATP binding cassette transporter ABCA1 modulates the secretion of apolipoprotein E from human monocyte-derived macrophages. FASEB J 15, 1555-1561. 

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