Multidrug resistance pumps (MDR pumps) also known Multidrug efflux pumps are a type of

efflux pump An efflux pump is an active transporter in cells that moves out unwanted material. Efflux pumps are an important component in bacteria, particularly in their ability to remove antibiotics. The efflux process can also involve the movement of hea ...

and

P-glycoprotein P-glycoprotein 1 (permeability glycoprotein, abbreviated as P-gp or Pgp) also known as multidrug resistance protein 1 (MDR1) or ATP-binding cassette sub-family B member 1 (ABCB1) or cluster of differentiation 243 (CD243) is an important protein ...

. MDR pumps in the

cell membrane The cell membrane (also known as the plasma membrane or cytoplasmic membrane, and historically referred to as the plasmalemma) is a biological membrane that separates and protects the interior of a cell from the outside environment (the extr ...

extrudes many foreign substances out of the cells and some pumps can have a broad specificity. MDR pumps exist in animals, fungi, and bacteria and likely evolved as a defense mechanism against harmful substances. There are seven families of MDRs and are grouped by homology, energy source, and overall structure. There are five major classes of efflux pumps in bacteria: the ATP-binding cassette (ABC) superfamily, the resistance nodulation division (RND) superfamily, the major facilitator superfamily (MFS), the small multidrug resistance (SMR) superfamily, and the multidrug and toxic compound extrusion (MATE) family. There are also two minor classes: the proteobacterial antimicrobial compound efflux (PACE) family, and the p-aminobenzoyl-glutamate transporter (AbgT) family. The ABC superfamily uses ATP as an energy source for export while the rest of the efflux pumps use proton motive force. Between them, the efflux pump classes cover a wide range of substrate specificities and are involved in numerous cellular processes including cell-to-cell communication, biofilm formation, virulence, and impart cellular protection through extrusion of toxic metabolic byproducts, toxic compounds, and clinical antibiotics. Extrusion of compounds by efflux pumps is energy dependent. ABC transporters use ATP hydrolysis for efflux. The rest of the characterized pumps use proton motive force. The increased use in antibiotics has resulted in a concomitant increase in antibiotic resistant bacteria. Pathogenic bacterial and fungal species have developed MDR pumps which efflux out many antibiotics and antifugals, increasing the concentration needed for their effect. In bacteria, overexpression of some efflux pumps can result in decreased susceptibility to multiple antibiotics. Because of their importance in drug evasion such as in

antibiotic resistance Antimicrobial resistance (AMR or AR) occurs when microbes evolve mechanisms that protect them from antimicrobials, which are drugs used to treat infections. This resistance affects all classes of microbes, including bacteria (antibiotic resis ...

, there is a growing about of research on Efflux pump inhibitors (EPIs). Many promising EPIs come from plant

secondary metabolite Secondary metabolites, also called ''specialised metabolites'', ''secondary products'', or ''natural products'', are organic compounds produced by any lifeform, e.g. bacteria, archaea, fungi, animals, or plants, which are not directly involved ...

s and small molecule compounds.

References

{{reflist Protein families Drug resistance