High impact information on ABCC1

• The ATP binding cassette (ABC) transporter, multidrug resistance protein 1 (MRP1/ABCC1), transports a broad spectrum of conjugated and unconjugated compounds, including natural product chemotherapeutic agents [1].
• In this study, we have investigated the importance of the COOH-terminal region of MRP1 for transport activity and basolateral plasma membrane trafficking [1].
• The COOH-terminal regions of some ABCC proteins have been implicated in protein trafficking, but the function of this region of MRP1 has not been defined [1].
• In contrast to results obtained with other ABCC proteins, we found that the COOH-proximal 30 amino acids of MRP1 can be removed without affecting trafficking to basolateral membranes [1].
• Ultimately, MRP2 displays higher selectivity for flavonoid type inhibition than MRP1 [2].

Biological context of ABCC1

• Multidrug resistance-associated protein (MRP) transport kinetics were determined by measuring the amount of BCECF transported out of the cell over time [3].
• For inhibition of MRP1, a quantitative structure activity relationship (QSAR) was obtained that indicates three structural characteristics to be of major importance for MRP1 inhibition by flavonoids: the total number of methoxylated moieties, the total number of hydroxyl groups and the dihedral angle between the B- and C-ring [2].

Anatomical context of ABCC1

• Like P-gp, the Vmax of BCECF for MRP-related transport was overwhelmingly higher in the BBM compared with the cultured cells [3].
• Co-treatment with isoflavones, curcumin and tetrahydrocurcumin, increased [3H]EGCG accumulation significantly in MDCKII/MRP1 and HT-29 cells [4].
• Furosemide secretion from these kidney-derived cell lines is probably not the primary result of any of the well characterized efflux transporters (P-gp, MRP1 or MRP2), although they may still play a role in the observed Caco-2 secretion [5].
• These results indicate that at least 26% of canine cutaneous mast cell tumors express PGP and/or MRP and that these tumors may be resistant to several anti-cancer drugs [6].

Associations of ABCC1 with chemical compounds

• The results were used to define the structural requirements of flavonoids necessary for potent inhibition of MRP1- and MRP2-mediated calcein transport in a cellular model [2].
• Several of the methoxylated flavonoids are among the best MRP1 inhibitors (IC(50) values, ranging between 2.7 and 14.3 microM) followed by robinetin, myricetin and quercetin (IC(50) values ranging between 13.6 and 21.8 microM) [2].
• Intracellular levels of EGCG, 4(")-O-methyl EGCG, and 4('),4(")-di-O-methyl EGCG were increased by 13-, 11-, and 3-fold, respectively, by indomethacin in MDCKII/MRP1 cells [4].
• Thus, in the absence of MRP1 efflux, transport of phloridzin by SGLT1 was clearly demonstrated [7].
• The results indicate that EGCG and its methyl metabolites are substrates for MRP1 and MRP2, but not for Pgp [4].

Other interactions of ABCC1

• For MRP-related transport, Km values for BCECF varied widely among the three BBB models with a rank order of MDCKII-MDR1 < BBMEC < BBM [3].

References