ABCMdb

ABCC4 p.Trp995Phe

None has been submitted yet.

Publications

PMID: 22542979 [PubMed] Wittgen HG et al: "Phenylalanine 368 of multidrug resistance-associated protein 4 (MRP4/ABCC4) plays a crucial role in substrate-specific transport activity."

No. Sentence Comment

46 Site-directed mutagenesis of MRP4 and generation of expression vectors and baculovirus The previously described Gateway entry vector containing the human MRP4 coding sequence [8] was used as a template for site-directed mutagenesis of the following amino acids: F368W, F368Y, F368A, W995F, W995Y, W995A, R998S, R998K, R998Y, and R998L. Login to comment
82 Kinetic analysis of MRP4 mutant proteins To determine the apparent Km and Vmax values of wild type and mutant MRP4 proteins F368W, F368Y, W995F, and W995Y, concentration curves were made for the different substrates. Login to comment
116 Transport via W995F and W995Y was not completely abolished, but the aromatic substitutions significantly decreased transport of all substrates compared to wild type MRP4. Login to comment
121 Kinetic properties of MRP4 wild type and F368W, F368Y, W995F, and W995Y mutants To further explore the mechanism by which the amino acid substitutions affected MRP4 transport activity, we determined the apparent affinity (Km) and maximum transport capacity (Vmax) of wild type MRP4 and mutants F368W, F368Y, W995F and W995Y for E217bG, cGMP, MTX, and folic acid. Login to comment
147 Kinetics of ATP-dependent transport of different substrates into membrane vesicles from HEK293 cells containing wild type MRP4 (&) or MRP4 mutants F368W (*), F368Y (Â), W995F (5), and W995Y (~). Login to comment
153 Table 1 Kinetic characteristics of transport via MRP4 mutants F368W, F368Y, W995F, and W995Y in comparison to wild type MRP4. Login to comment
154 E217bG cGMP MTX Folic acid Km (mM) Vmax (%) Km (mM) Vmax (%) Km (mM) Vmax (%) Km (mM) Vmax (%) MRP4 17 Æ 2 99 Æ 3 630 Æ 67 99 Æ 5 170 Æ 30 97 Æ 6 250 Æ 73 100 Æ 13 F368W 17 Æ 3 310 Æ 14*** >2000 n.d. 160 Æ 36 53 Æ 4* 240 Æ 100 85 Æ 15 F368Y 31 Æ 3 130 Æ 5*** 480 Æ 63 110 Æ 7 260 Æ 89 130 Æ 17 300 Æ 182 42 Æ 12*** W995F 54 Æ 24** 42 Æ 7*** 360 Æ 46 21 Æ 1** 150 Æ 81 19 Æ 3*** 350 Æ 275 31 Æ 12*** W995Y 13 Æ 4 26 Æ 2*** 1800 Æ 1020 94 Æ 36 130 Æ 48 16 Æ 2*** 390 Æ 116 61 Æ 9** n.d. not determined: concentration of cGMP in the experiment was not high enough to accurately determine Vmax. Login to comment
179 The decreased transport of W995F and W995Y appeared to be mainly caused by a decreased Vmax, indicating a decreased catalytic turnover number of these MRP4 mutants. Login to comment
47 Site-directed mutagenesis of MRP4 and generation of expression vectors and baculovirus The previously described Gateway entry vector containing the human MRP4 coding sequence [8] was used as a template for site-directed mutagenesis of the following amino acids: F368W, F368Y, F368A, W995F, W995Y, W995A, R998S, R998K, R998Y, and R998L. Login to comment
148 Kinetics of ATP-dependent transport of different substrates into membrane vesicles from HEK293 cells containing wild type MRP4 (&) or MRP4 mutants F368W (*), F368Y (), W995F (5), and W995Y (~). Login to comment
155 E217bG cGMP MTX Folic acid Km (mM) Vmax (%) Km (mM) Vmax (%) Km (mM) Vmax (%) Km (mM) Vmax (%) MRP4 17 2 99 3 630 67 99 5 170 30 97 6 250 73 100 13 F368W 17 3 310 14*** >2000 n.d. 160 36 53 4* 240 100 85 15 F368Y 31 3 130 5*** 480 63 110 7 260 89 130 17 300 182 42 12*** W995F 54 24** 42 7*** 360 46 21 1** 150 81 19 3*** 350 275 31 12*** W995Y 13 4 26 2*** 1800 1020 94 36 130 48 16 2*** 390 116 61 9** n.d. not determined: concentration of cGMP in the experiment was not high enough to accurately determine Vmax. Login to comment