ABCMdb

ABCC1 p.Asp792Ala

Predicted by SNAP2:	A: D (95%), C: D (95%), E: D (95%), F: D (95%), G: D (95%), H: D (95%), I: D (95%), K: D (95%), L: D (95%), M: D (95%), N: D (95%), P: D (95%), Q: D (95%), R: D (95%), S: D (95%), T: D (95%), V: D (95%), W: D (95%), Y: D (95%),
Predicted by PROVEAN:	A: D, C: D, E: D, F: D, G: D, H: D, I: D, K: D, L: D, M: D, N: D, P: D, Q: D, R: D, S: D, T: D, V: D, W: D, Y: D,

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[hide] ATP binding to the first nucleotide-binding domain... J Biol Chem. 2002 Feb 15;277(7):5110-9. Epub 2001 Dec 7. Hou YX, Cui L, Riordan JR, Chang XB
ATP binding to the first nucleotide-binding domain of multidrug resistance protein MRP1 increases binding and hydrolysis of ATP and trapping of ADP at the second domain.
J Biol Chem. 2002 Feb 15;277(7):5110-9. Epub 2001 Dec 7., 2002-02-15 [PMID:11741902]

Abstract [show]
Multidrug resistance protein (MRP1) utilizes two non-equivalent nucleotide-binding domains (NBDs) to bind and hydrolyze ATP. ATP hydrolysis by either one or both NBDs is essential to drive transport of solute. Mutations of either NBD1 or NBD2 reduce solute transport, but do not abolish it completely. How events at these two domains are coordinated during the transport cycle have not been fully elucidated. Earlier reports (Gao, M., Cui, H. R., Loe, D. W., Grant, C. E., Almquist, K. C., Cole, S. P., and Deeley, R. G. (2000) J. Biol. Chem. 275, 13098-13108; Hou, Y., Cui, L., Riordan, J. R., and Chang, X. (2000) J. Biol. Chem. 275, 20280-20287) indicate that intact ATP is observed bound at NBD1, whereas trapping of the ATP hydrolysis product, ADP, occurs predominantly at NBD2 and that trapping of ADP at NBD2 enhances ATP binding at NBD1 severalfold. This suggested transmission of a positive allosteric interaction from NBD2 to NBD1. To assess whether ATP binding at NBD1 can enhance the trapping of ADP at NBD2, photoaffinity labeling experiments with [alpha-(32)P]8-N(3)ADP were performed and revealed that when presented with this compound labeling of MRP1 occurred at both NBDs. However, upon addition of ATP, this labeling was enhanced 4-fold mainly at NBD2. Furthermore, the nonhydrolyzable ATP analogue, 5'-adenylylimidodiphosphate (AMP-PNP), bound preferentially to NBD1, but upon addition of a low concentration of 8-N(3)ATP, the binding at NBD2 increased severalfold. This suggested that the positive allosteric stimulation from NBD1 actually involves an increase in ATP binding at NBD2 and hydrolysis there leading to the trapping of ADP. Mutations of Walker A or B motifs in either NBD greatly reduced their ability to be labeled by [alpha-(32)P]8-N(3)ADP as well as by either [alpha-(32)P]- or [gamma-(32)P]8-N(3)ATP (Hou et al. (2000), see above). These mutations also strongly diminished the enhancement by ATP of [alpha-(32)P]8-N(3)ADP labeling and the transport activity of the protein. Taken together, these results demonstrate directly that events at NBD1 positively influence those at NBD2. The interactions between the two asymmetric NBDs of MRP1 protein may enhance the catalytic efficiency of the MRP1 protein and hence of its ATP-dependent transport of conjugated anions out of cells.

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No. Sentence Comment
50 Stable cell lines expressing wild-type and mutant MRP1s, K684L, D792A, K1333L, and D1454L/E1455L were established previously (2, 31). Login to comment
117 Essentially the stimulation was much reduced in the NBD1 mutants, K684L and D792A (Fig. 4, C and D), and in the NBD2 mutants, K1333L and D1454L/E1455L (Fig. 4, E and F), and the stimulation effects were shifted to higher ATP concentrations (Fig. 4, C-F). Login to comment
173 Lane 1, 10 ␮g of wild-type MRP1; lane 2, 15 ␮g of K684L; lane 3, 20 ␮g of D792A; lane 4, 10 ␮g of K1333L; lane 5, 10 ␮g of D1454L/E1455L. Login to comment
175 The results for K684L and D792A are the average of three independent experiments and for K1333L and D1454L/E1455L are the average of two independent experiments. C, influence of ATP on the [␣-32 P]8-N3ADP labeling of K684L. Login to comment
176 15 ␮g of K684L was labeled in the presence of varying amounts of ATP indicated above each lane. D, influence of ATP on the [␣-32 P]8-N3ADP labeling of D792A. Login to comment
177 20 ␮g of D792A was labeled in the presence of varying amount of ATP indicated above each lane. Login to comment

[hide] ATP binding, not hydrolysis, at the first nucleoti... J Biol Chem. 2003 Feb 7;278(6):3599-605. Epub 2002 Nov 27. Hou YX, Riordan JR, Chang XB
ATP binding, not hydrolysis, at the first nucleotide-binding domain of multidrug resistance-associated protein MRP1 enhances ADP.Vi trapping at the second domain.
J Biol Chem. 2003 Feb 7;278(6):3599-605. Epub 2002 Nov 27., 2003-02-07 [PMID:12458196]

Abstract [show]
Multidrug resistance-associated protein (MRP1) transports solutes in an ATP-dependent manner by utilizing its two nonequivalent nucleotide binding domains (NBDs) to bind and hydrolyze ATP. We found that ATP binding to the first NBD of MRP1 increases binding and trapping of ADP at the second domain (Hou, Y., Cui, L., Riordan, J. R., and Chang, X. (2002) J. Biol. Chem. 277, 5110-5119). These results were interpreted as indicating that the binding of ATP at NBD1 causes a conformational change in the molecule and increases the affinity for ATP at NBD2. However, we did not distinguish between the possibilities that the enhancement of ADP trapping might be caused by either ATP binding alone or hydrolysis. We now report the following. 1) ATP has a much lesser effect at 0 degrees C than at 37 degrees C. 2) After hexokinase treatment, the nonhydrolyzable ATP analogue, adenyl 5'-(yl iminodiphosphate), does not enhance ADP trapping. 3) Another nonhydrolyzable ATP analogue, adenosine 5'-(beta,gamma-methylene)triphosphate, whether hexokinase-treated or not, causes a slight enhancement. 4) In contrast, the hexokinase-treated poorly hydrolyzable ATP analogue, adenosine 5'-O-(thiotriphosphate) (ATPgammaS), enhances ADP trapping to a similar extent as ATP under conditions in which ATPgammaS should not be hydrolyzed. We conclude that: 1) ATP hydrolysis is not required to enhance ADP trapping by MRP1 protein; 2) with nucleotides having appropriate structure such as ATP or ATPgammaS, binding alone can enhance ADP trapping by MRP1; 3) the stimulatory effect on ADP trapping is greatly diminished when the MRP1 protein is in a "frozen state" (0 degrees C); and 4) the steric structure of the nucleotide gamma-phosphate is crucial in determining whether binding of the nucleotide to NBD1 of MRP1 protein can induce the conformational change that influences nucleotide trapping at NBD2.

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No. Sentence Comment
226 Indeed, mutations of K684L and D792A greatly diminish the ATP enhancing effect on ADP trapping (34). Login to comment

[hide] Insight in eukaryotic ABC transporter function by ... FEBS Lett. 2006 Feb 13;580(4):1064-84. Epub 2006 Jan 19. Frelet A, Klein M
Insight in eukaryotic ABC transporter function by mutation analysis.
FEBS Lett. 2006 Feb 13;580(4):1064-84. Epub 2006 Jan 19., 2006-02-13 [PMID:16442101]

Abstract [show]
With regard to structure-function relations of ATP-binding cassette (ABC) transporters several intriguing questions are in the spotlight of active research: Why do functional ABC transporters possess two ATP binding and hydrolysis domains together with two ABC signatures and to what extent are the individual nucleotide-binding domains independent or interacting? Where is the substrate-binding site and how is ATP hydrolysis functionally coupled to the transport process itself? Although much progress has been made in the elucidation of the three-dimensional structures of ABC transporters in the last years by several crystallographic studies including novel models for the nucleotide hydrolysis and translocation catalysis, site-directed mutagenesis as well as the identification of natural mutations is still a major tool to evaluate effects of individual amino acids on the overall function of ABC transporters. Apart from alterations in characteristic sequence such as Walker A, Walker B and the ABC signature other parts of ABC proteins were subject to detailed mutagenesis studies including the substrate-binding site or the regulatory domain of CFTR. In this review, we will give a detailed overview of the mutation analysis reported for selected ABC transporters of the ABCB and ABCC subfamilies, namely HsCFTR/ABCC7, HsSUR/ABCC8,9, HsMRP1/ABCC1, HsMRP2/ABCC2, ScYCF1 and P-glycoprotein (Pgp)/MDR1/ABCB1 and their effects on the function of each protein.

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No. Sentence Comment
161 The variant D792L was unable to mature conformationally and D792A led to an accumulation of equal amounts of mature and immature proteins but still resulted in defective nucleotide interaction and organic anion transport, indicating that nucleotide hydrolysis at NBD1 was essential for MRP1 function [101]. Login to comment

[hide] The hydroxyl group of S685 in Walker A motif and t... Biochim Biophys Acta. 2008 Feb;1778(2):454-65. Epub 2007 Nov 29. Yang R, Scavetta R, Chang XB
The hydroxyl group of S685 in Walker A motif and the carboxyl group of D792 in Walker B motif of NBD1 play a crucial role for multidrug resistance protein folding and function.
Biochim Biophys Acta. 2008 Feb;1778(2):454-65. Epub 2007 Nov 29., [PMID:18088596]

Abstract [show]
Structural analysis of MRP1-NBD1 revealed that the Walker A S685 forms hydrogen-bond with the Walker B D792 and interacts with magnesium and the beta-phosphate of the bound ATP. We have found that substitution of the D792 with leucine resulted in misfolding of the protein. In this report we tested whether substitution of the S685 with residues that prevent formation of this hydrogen-bond would also cause misfolding. Indeed, substitution of the S685 with residues potentially preventing formation of this hydrogen-bond resulted in misfolding of the protein. In addition, some substitutions that might form hydrogen-bond with D792 also yielded immature protein. All these mutants are temperature-sensitive variants. However, these complex-glycosylated mature mutants prepared from the cells grown at 27 degrees C still significantly affect ATP binding and ATP-dependent solute transport. In contrast, substitution of the S685 with threonine yielded complex-glycosylated mature protein that is more active than the wild-type MRP1, indicating that the interaction between the hydroxyl group of 685 residue and the carboxyl group of D792 plays a crucial role for the protein folding and the interactions of the hydroxyl group at 685 with magnesium and the beta-phosphate of the bound ATP play an important role for ATP-binding and ATP-dependent solute transport.

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Sentences [show]
No. Sentence Comment
21 However, substitution of the acidic amino acid D792 in Walker B motif with a hydrophobic residue, such as D792L- or D792A-mutated MRP1 [20,23], caused misfolding of the protein and prevented further analysis of the mutated protein. Login to comment
24 However, this mechanism of protein folding may not be applied to the misfolding caused by substitution of the acidic amino acid with a hydrophobic residue, such as D792L- or D792A-mutated MRP1 [20,23]. Login to comment
27 We suspected that D792A or D792L mutation abolished the hydrogen-bond formation between D792 and S685 and resulted in misfolding of the mutated MRP1 protein. Login to comment
94 We suspected that D792A or D792L mutation abolished the hydrogen-bond formation between D792 and S685 and resulted in misfolding of the mutated MRP1 protein. Login to comment

[hide] Mutations of the Walker B motif in the first nucle... Arch Biochem Biophys. 2001 Aug 1;392(1):153-61. Cui L, Hou YX, Riordan JR, Chang XB
Mutations of the Walker B motif in the first nucleotide binding domain of multidrug resistance protein MRP1 prevent conformational maturation.
Arch Biochem Biophys. 2001 Aug 1;392(1):153-61., [PMID:11469806]

Abstract [show]
ATP-binding cassette (ABC) transporters couple the binding and hydrolysis of ATP to the translocation of solutes across biological membranes. The so-called "Walker motifs" in each of the nucleotide binding domains (NBDs) of these proteins contribute directly to the binding and the catalytic site for the MgATP substrate. Hence mutagenesis of residues in these motifs may interfere with function. This is the case with the MRP1 multidrug transporter. However, interpretation of the effect of mutation in the Walker B motif of NBD1 (D792L/D793L) was confused by the fact that it prevented biosynthetic maturation of the protein. We have determined now that this latter effect is entirely due to the D792L substitution. This variant is unable to mature conformationally as evidenced by its remaining more sensitive to trypsin digestion in vitro than the mature wild-type protein. In vivo, the core-glycosylated form of that mutant is retained in the endoplasmic reticulum and degraded by the proteasome. A different substitution of the same residue (D792A) had a less severe effect enabling accumulation of approximately equal amounts of mature and immature MRP1 proteins in the membrane vesicles but still resulted in defective nucleotide interaction and organic anion transport, indicating that nucleotide hydrolysis at NBD1 is essential to MRP1 function.

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No. Sentence Comment
8 A different substitution of the same residue (D792A) had a less severe effect enabling accumulation of approximately equal amounts of mature and immature MRP1 proteins in the membrane vesicles but still resulted in defective nucleotide interaction and organic anion transport, indicating that nucleotide hydrolysis at NBD1 is essential to MRP1 function. Login to comment
18 A different substitution of the important residue (D792A) only partially impaired maturation yet still 1 To whom correspondence and reprint requests should be addressed. Login to comment
36 The aspartic acid residues at positions of 792 and 793 were mutated either to alanine (Fig. 1B, D792A) or leucine residues (Fig. 1B, D792L and D793L) using the QuikChange Site Directed Mutagenesis kit. Login to comment
43 The cell lines expressing D792A, D792L, and D793L were generated using the same procedures (9). Login to comment
90 D793L is indistinguishable from wild-type, whereas D792L is similar to the double mutant indicating that the substitution at this position is primarily responsible for the misprocessing. Login to comment
91 However, when this residue was replaced by alanine (D792A) instead of leucine a detectable mature band was also present. Login to comment
93 These were more apparent in a longer exposure of the same blot (Fig. 2B), especially in D792L/D793L, where, in addition to the major 170-kDa species, bands of approximately 160, 130, 100, and 30 kDa can be seen. Login to comment
94 Of these four only the 130- and 30-kDa bands are seen in the D792A and D792L lanes. Login to comment
99 It is also apparent that the mature form of MRP1 is enriched in the membrane fraction compared with the whole cell lysate; this is especially obvious with D792A, where there appears to be about equal amounts of the immature and mature bands in the membrane fraction (Fig. 2C). Login to comment
124 The following amounts of protein were loaded in each lane: 0.5 ␮g of wild-type MRP1; 8 ␮g of D792A; 18 ␮g of D792L; 0.5 ␮g of D793L; 20 ␮g of D792L/D793L. Login to comment
132 The following amounts were loaded in each lane: 0.5 ␮g of wild-type MRP1; 2 ␮g of D792A; 4 ␮g of D792L; 0.35 ␮g of D793L; 8 ␮g of D792L/D793L. Login to comment
133 The ratio of mature to immature protein in membrane vesicles of D792A and D792L are much higher than in whole cell lysates (Fig. 2A). Login to comment
136 Lanes 1 and 2, 1 ␮g of D793L cell lysates in each lane; Lanes 3 and 4, 4 ␮g of D792A cell lysates in each lane; Lanes 5 and 6, 10 ␮g of D792L/D793L cell lysates in each lane. Login to comment
137 Both the 170-kDa core-glycosylated MRP1 protein from either D793L, D792A, or D792L/D793L and 160-kDa degradation product from D792L/D793L were decreased in size by treatment with endoglycosidase H. pressing either the D792L or D792L/D793L mutants with either lactacystin or ALLN resulted in the total disappearance of the immature forms from nonionic detergent soluble fractions and appearance in insoluble pellets. Login to comment
155 This comparison is most obvious with the D792A mutant where the membranes subjected to trypsin digestion contain approximately equal amounts of immature and mature species (Fig. 5C). Login to comment
168 It was impossible to tell if the dysfunction of the D792L mutation was secondary to its inability to mature conformationally. Login to comment
169 However, since approximately half of the D792A protein in the membrane was mature it was possible to assay its functional capability. Login to comment
171 Figure 6 shows labeling of the wild-type and the innocuous D793L variant which matures normally. Login to comment
172 However, there was greatly reduced labeling of the variants in which D792 was substituted including D792A where there is considerable mature protein. Login to comment
174 Since hydrolysis is believed to drive MRP1 transport it would be expected that the mature D792A protein would not be capable of active transport. Login to comment
175 The data in Fig. 7 confirm this expectation, i.e., there is not significantly more ATP-dependent LTC4 uptake by vesicles containing D792A protein that does mature than by the other variants that do not mature (Fig. 7, D792L and D792L/D793L), nor by the NBD2 mutants (Fig. 7, K1333L and D1454L/E1455L) that do mature but have difficulties to hydrolyze ATP and to trap the hydrolysis product, ADP (8). Login to comment
184 However, when a different substitution, D792A, was made considerable maturation occurred although still less than wild-type (Figs. 2B and 2C). Login to comment
203 (B) K684L, 0.6 ␮g protein in each lane. Login to comment
204 (C) D792A, 0.73 ␮g protein in each lane. Login to comment
98 It is also apparent that the mature form of MRP1 is enriched in the membrane fraction compared with the whole cell lysate; this is especially obvious with D792A, where there appears to be about equal amounts of the immature and mature bands in the membrane fraction (Fig. 2C). Login to comment
123 The following amounts of protein were loaded in each lane: 0.5 òe;g of wild-type MRP1; 8 òe;g of D792A; 18 òe;g of D792L; 0.5 òe;g of D793L; 20 òe;g of D792L/D793L. Login to comment
131 The following amounts were loaded in each lane: 0.5 òe;g of wild-type MRP1; 2 òe;g of D792A; 4 òe;g of D792L; 0.35 òe;g of D793L; 8 òe;g of D792L/D793L. Login to comment
135 Lanes 1 and 2, 1 òe;g of D793L cell lysates in each lane; Lanes 3 and 4, 4 òe;g of D792A cell lysates in each lane; Lanes 5 and 6, 10 òe;g of D792L/D793L cell lysates in each lane. Login to comment
154 This comparison is most obvious with the D792A mutant where the membranes subjected to trypsin digestion contain approximately equal amounts of immature and mature species (Fig. 5C). Login to comment
173 Since hydrolysis is believed to drive MRP1 transport it would be expected that the mature D792A protein would not be capable of active transport. Login to comment
183 However, when a different substitution, D792A, was made considerable maturation occurred although still less than wild-type (Figs. 2B and 2C). Login to comment