ABCMdb

PMID: 15459206

Westlake CJ, Payen L, Gao M, Cole SP, Deeley RG
Identification and characterization of functionally important elements in the multidrug resistance protein 1 COOH-terminal region.
J Biol Chem. 2004 Dec 17;279(51):53571-83. Epub 2004 Sep 30., 2004-12-17 [PubMed]

Sentences

No. Mutations Sentence Comment

130 ABCC1 p.Val1497Ala It has recently been reported that Ala substitution of Val1497 -Ile1498 -Val1499 -Leu1500 in the COOH-terminal region of MRP1 impaired protein maturation in BHK-21 cells (41). Login to comment 224 ABCC1 p.Leu1500Ala ABCC1 p.Leu1488Ala ABCC1 p.Phe1521Ala ABCC1 p.Ile1491Ala The L1488A, I1491A, L1500A, and F1521A mutations reduced uptake by ϳ50, 40, 80, and 60%, respectively (Table I). Login to comment 227 ABCC1 p.Leu1500Ala ABCC1 p.Ile1498Ala ABCC1 p.Leu1514Ala ABCC1 p.Val1499Ala ABCC1 p.Leu1515Ala The L1497A/I1498A/V1499A/L1500A mutation essentially inactivated the protein, and the double L1514A/L1515A mutation reduced transport by 80%. Login to comment 228 ABCC1 p.Leu1514Ala ABCC1 p.Leu1515Ala Similar to the MRP11-1527, the L1514A/L1515A mutant had a 4-fold increase in the Km for ATP and an approximate 2.5-fold decrease in the Vmax for LTC4 transport. Login to comment 229 ABCC1 p.Gly1529Ala ABCC1 p.Asp1527Ala In contrast, the D1527A/G1529A double mutation increased LTC4 uptake by ϳ25% (Table I). Login to comment 241 ABCC1 p.Leu1515Ile ABCC1 p.Leu1514Ile ABCC1 p.Leu1514Val ABCC1 p.Leu1515Val Consequently, we created two additional double mutations, L1514V/L1515V and L1514I/L1515I. Login to comment 245 ABCC1 p.Phe1521Tyr Consistent with a requirement for an aromatic side chain, mutation of Phe1521 to Tyr had no effect on LTC4 transport, whereas substitution with Gly, Gln, or Glu reduced LTC4 transport activity by ϳ60, ϳ70, and ϳ75%, respectively (Table I). Login to comment 247 ABCC1 p.Met1524Gly In contrast to Ala substitution, the M1524G mutation decreased LTC4 transport by ϳ35%. Login to comment 248 ABCC1 p.Met1524Gly ABCC1 p.Ala1525Gly Furthermore, although a single mutation of the adjacent Ala1524 to Gly did not affect activity, the double mutation M1524G/A1525G reduced LTC4 transport by ϳ75% (Table I). Login to comment 256 ABCC1 p.Val1497Ala ABCC1 p.Leu1500Ala ABCC1 p.Leu1500Ala ABCC1 p.Leu1488Ala ABCC1 p.Phe1521Ala ABCC1 p.Ile1491Ala ABCC1 p.Ile1498Ala ABCC1 p.Leu1514Ala ABCC1 p.Val1499Ala ABCC1 p.Val1499Ala ABCC1 p.Leu1515Ala ABCC1 p.Gly1529Ala ABCC1 p.Asp1527Ala ABCC1 p.Leu1515Ile ABCC1 p.Leu1514Ile ABCC1 p.Leu1514Val ABCC1 p.Leu1515Val ABCC1 p.Phe1521Tyr ABCC1 p.Met1524Gly ABCC1 p.Met1524Gly ABCC1 p.Ala1525Gly ABCC1 p.Ala1525Gly ABCC1 p.Gln1516Ala ABCC1 p.Tyr1522Ala ABCC1 p.Leu1520Ala ABCC1 p.Met1492Ala ABCC1 p.Met1524Ala ABCC1 p.Asp1501Ala ABCC1 p.Gly1509Ala ABCC1 p.Gly1519Ala ABCC1 p.Phe1521Gly ABCC1 p.Phe1521Glu ABCC1 p.Lys1526Ala ABCC1 p.Gly1503Ala ABCC1 p.Ile1505Ala ABCC1 p.Ser1523Ala ABCC1 p.Glu1507Ala ABCC1 p.Pro1511Ala ABCC1 p.Phe1521Gln ABCC1 p.Arg1518Ala Related structure COOH-terminal mutation Expression (relative to WT) LTC4 uptake (percentage of WT) Km Vmax -fold % ␮M pmol mg-1 min-1 Helix C3 L1488A 1.2 48 Ϯ 2 I1491A 1.2 59 Ϯ 2 M1492A 1.4 89 Ϯ 3 Sheet C2 V1499A 1.0 94 Ϯ 6 L1500A 1.1 22 Ϯ 1 V1497A/I1498A/V1499A/L1500A 1.0 3.6 Ϯ 0.8 D1501A 1.0 90 Ϯ 5 Sheet C1 G1503A 0.8 100 Ϯ 4 I1505A 0.5 90 Ϯ 10 E1507A 0.8 108 Ϯ 6 G1509A 0.8 113 Ϯ 9 Helix C2 P1511A 1.0 82 Ϯ 6 L1514A/L1515A 1.2 18 Ϯ 2 623 84 L1514V/L1515V 1.0 75 Ϯ 1 L1514I/L1515I 1.0 94 Ϯ 2 Q1516A 1.2 94 Ϯ 3 R1518A 0.8 103 Ϯ 10 G1519A 1.1 100 Ϯ 10 L1520A 1.3 110 Ϯ 3 Helix C1 F1521A 0.8 38 Ϯ 1 F1521Y 1.0 105 Ϯ 2 F1521G 0.9 40 Ϯ 1 F1521Q 1.0 30 Ϯ 1 F1521E 1.0 22 Ϯ 1 Y1522A 1.2 90 Ϯ 5 S1523A 1.1 103 Ϯ 6 M1524A 1.0 130 Ϯ 2 M1524G 1.0 65 Ϯ 3 A1525G 1.0 100 Ϯ 4 M1524G/A1525G 1.0 21 Ϯ 3 733 68 K1526A 2.5 85 Ϯ 2 D1527A/G1529A 3.0 123 Ϯ 4 tation impaired nucleotide binding and trapping at NBD2 to an extent comparable with that resulting from removal of the COOH-terminal 4 amino acids (not shown). Login to comment 279 ABCC1 p.Met1524Gly ABCC1 p.Ala1525Gly This suggestion is further supported by the effect of introducing destabilizing Gly mutations into this helix, as exemplified by the double M1524G/A1525G mutation, which had the same effect on activity as deletion of the terminal 4 or 9 amino acids. Login to comment 302 ABCC1 p.Leu1515Ile ABCC1 p.Leu1514Ile ABCC1 p.Leu1515Val Consistent with the presence of Leu-Val and Leu-Ile, rather than di-Leu, in some ABC proteins, substitution of Leu1514 and Leu1515 with Ile or Val rather than Ala had minimal effect on LTC4 transport activity. Login to comment