Efflux pump

An efflux pump is a membrane protein or protein complex that moves substances from a cell’s interior to its exterior. It can export drugs, toxins, metabolites, and other molecules.

ATP-binding cassette transporter: A membrane transporter that uses ATP hydrolysis to move substrates across a membrane. This pump family powers drug export directly with ATP.
Multidrug resistance: Resistance to multiple drugs, often caused by mechanisms that reduce drug accumulation or alter drug targets. Broad-specificity pumps can lower intracellular levels of several unrelated drugs.
Cell membrane: A selectively permeable lipid bilayer that separates a cell’s interior from its surroundings. Efflux pumps span or associate with this barrier to move substrates across it.
Drug target modification: A resistance mechanism in which changes to a drug’s cellular target reduce the drug’s effectiveness. Unlike target modification, efflux reduces how much drug reaches its target.
Efflux assay: An experimental method for measuring how quickly cells or vesicles export a probe compound. Assays help separate pump-mediated export from reduced uptake or other resistance mechanisms.
Resistance-nodulation-cell division transporter: A family of membrane transporters that commonly exports drugs and toxins from Gram-negative bacteria. These transporters form major drug-export systems in Gram-negative bacteria.
Antibiotic resistance: The ability of bacteria to survive exposure to antibiotics that would normally inhibit or kill them. Efflux is one mechanism bacteria use to resist antibiotics.
Active transport: Movement of substances across a membrane using energy, often against a concentration gradient. Efflux can concentrate exported substances outside the cell despite opposing gradients.
Drug-inactivating enzyme: An enzyme that chemically modifies or degrades a drug, reducing its activity. Enzymatic inactivation destroys or alters drugs rather than transporting them out.
Transport kinetics: The quantitative study of transport rates and their dependence on substrate concentration and other conditions. Kinetic measurements reveal pump capacity, affinity, and possible saturation.

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