ABCC1 p.Asp792Glu
| 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, 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
227 Interestingly, mutation of D792E, which did not significantly change the negative charge at that position, also greatly diminished the ATP enhancement effect on ADP trapping,2 indicating that the distance between the negative charged residue, Asp-792, and the ␥-phosphate of ATP is also very important.
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ABCC1 p.Asp792Glu 12458196:227:27
status: NEW