The protein was named multidrug resistance protein 1 (MRP1).
In 1992, a second MDR-causing transporter named multidrug resistance-associated protein 1 (MRP1) was reported [2] and found to cause resistance to xenobiotics and anticancer agents.
This class of ATP-binding cassette transporters constitutes efflux pumps, also named multidrug resistance associated proteins (MRP), and many proteins of this class have been implicated in reducing the cellular concentration of toxic compounds [ 68, 69].
The family of ATP-binding cassette (ABC) transporters is divided into subfamilies: the multidrug-resistance proteins or P-glycoproteins (Abcb subfamily, HUGO names ABCB1-11), the multidrug resistance-related proteins MRPs (Abcc subfamily, HUGO names ABCC1-5) and the breast cancer-resistance protein (BCRP, HUGO names ABCG1-8) [ 195].
A second recent study (Eldakak et al., 2010) has identified a new class of proteins that are retained in the yeast mother cell and that appear to be limiting for replicative lifespan, the MDR transporter proteins (so named because they mediate multidrug resistance in some cancers).
The first eukaryotic ABC transporter discovered was the human (h) drug efflux transporter MDR (multidrug resistance) P-glycoprotein (hABCB1/MDR1), the name of which reflects that its expression in cancers can cause a decreased cellular drug accumulation (initially referred to as drug permeability, 'P'), resulting in the resistance of tumours against chemotherapy [ 14, 15].
This could cause, for example, the deactivation of cell cycle checkpoints or enhanced exclusion of therapeutic reagents or increased expression of multidrug-resistance proteins, leading, as the name of the latter example already suggests, to resistance not only against already used therapeutic avenues but also against possible future approaches.
The polymyxin E named colistin and polymyxin B have been used to treat several infections caused by multidrug resistant Pseudomonas aeruginosa (MDR-PA) isolates, which are resistant to aminoglycosides, cephalosporin and penicillins anti-pseudomonas, quinolones, monobactams and carbapenem [ 2, 3].
Multidrug resistance proteins (MRPs) are members of the C family of a group of proteins named ATP-binding cassette (ABC) transporters.
One multidrug-resistant strain, named K. pneumoniae KF3, was chosen as a representative and its three plasmids were sequenced.
It is curable through multidrug therapy.
