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Conformational Changes of the Multispecific Transporter Organic Anion Transporter 1 (OAT1/SLC22A6) Suggests a Molecular Mechanism for Initial Stages of Drug and Metabolite Transport

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Abstract

The solute carrier (SLC) family of transporters play key roles in the movement of charged organic ions across the blood–urine, blood–cerebrospinal fluid, and blood–brain barriers and thus mediate the absorption, disposition, and elimination of many common pharmaceuticals (i.e., nonsteroidal anti-inflammatory drug (NSAIDs), antibiotics, and diuretics). They have also been proposed to participate in a remote sensing and signaling network involving small molecules. Nevertheless, other than possessing a 12-transmembrane α-helical topology comprised of two six-helix hemidomains interacting through a long loop, the structural and mechanistic details for these transporters remains unclear. Recent crystallographic studies of bacterial homologs support the idea of a “switching” mechanism, which allows for periodic changes in the overall transporter configuration and cyclic opening of the transporter to the extracellular or cytoplasmic sides of the membrane. To investigate this, computational modeling based on our recent study of glycerol-3-phosphate transporter (GlpT) (Tsigelny et al. J Bioinform Comput Biol 6:885–904, 2008) was performed for organic anion transporter 1 (OAT1/SLC22A6, originally identified as NKT), the prototypical member of this family. OAT1 was inserted into an artificial phospholipid bilayer and the positional change of the six-helix hemidomains relative to each other was followed for 100 ns. The hemidomains were found to tilt relative to each other while their configuration is mostly inflexible. Since the modeling was performed for about 100 ns, the data suggest that this tilting mechanism might explain the early steps in the transport of organic anionic metabolites, drugs, and toxins by this clinically important transporter.

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Abbreviations

GlpT:

Glycerol-3-phosphate transporter

OAT1:

Organic anion transporter 1

SLC:

Solute carrier

MFS:

Major facilitator superfamily

NKT:

Novel kidney transporter

NSAID:

Nonsteroidal anti-inflammatory drug

GLUT1:

Glucose transporter 1, hexose facilitator

G6PT:

Glucose 6-phosphate transporter

SA:

Simulated annealing

MD:

Molecular dynamics

POPC:

1-Palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine

NPT ensemble:

Isothermal-isobaric ensemble: moles (N), pressure (P), and temperature (T)

PME:

Particle-Mesh Ewald

αKG:

α-ketoglutarate

ABC:

ATP-binding cassette

VMD:

Visual molecular dynamics

References

  1. Abramson, J., Iwata, S., & Kaback, H. R. (2004). Lactose permease as a paradigm for membrane transport proteins (review). Molecular Membrane Biology, 21, 227–236.

    Article  CAS  PubMed  Google Scholar 

  2. Abramson, J., Smirnova, I., Kasho, V., Verner, G., Kaback, H. R., & Iwata, S. (2003). Structure and mechanism of the lactose permease of Escherichia coli. Science, 301, 610–615.

    Article  CAS  PubMed  Google Scholar 

  3. Auer, M., Kim, M. J., Lemieux, M. J., Villa, A., Song, J., Li, X. D., et al. (2001). High-yield expression and functional analysis of Escherichia coli glycerol-3-phosphate transporter. Biochemistry, 40, 6628–6635.

    Article  CAS  PubMed  Google Scholar 

  4. Eiglmeier, K., Boos, W., & Cole, S. T. (1987). Nucleotide sequence and transcriptional startpoint of the GlpT gene of Escherichia coli: Extensive sequence homology of the glycerol-3-phosphate transport protein with components of the hexose-6-phosphate transport system. Molecular Microbiology, 1, 251–258.

    Article  CAS  PubMed  Google Scholar 

  5. Hayashi, S., Koch, J. P., & Lin, E. C. (1964). Active transport of L-alpha-glycerophosphate in Escherichia coli. Journal of Biological Chemistry, 239, 3098–3105.

    CAS  PubMed  Google Scholar 

  6. Henderson, P. J. (1993). The 12-transmembrane helix transporters. Current Opinion in Cell Biology, 5, 708–721.

    Article  CAS  PubMed  Google Scholar 

  7. Huang, Y., Lemieux, M. J., Song, J., Auer, M., & Wang, D. N. (2003). Structure and mechanism of the glycerol-3-phosphate transporter from Escherichia coli. Science, 301, 616–620.

    Article  CAS  PubMed  Google Scholar 

  8. Pao, S. S., Paulsen, I. T., & Saier, M. H., Jr. (1998). Major facilitator superfamily. Microbiology and Molecular Biology Reviews, 62, 1–34.

    CAS  PubMed  Google Scholar 

  9. Reizer, J., Finley, K., Kakuda, D., MacLeod, C. L., Reizer, A., & Saier, M. H., Jr. (1993). Mammalian integral membrane receptors are homologous to facilitators and antiporters of yeast, fungi, and eubacteria. Protein Science, 2, 20–30.

    Article  CAS  PubMed  Google Scholar 

  10. Lopez-Nieto, C. E., You, G., Bush, K. T., Barros, E. J., Beier, D. R., & Nigam, S. K. (1997). Molecular cloning and characterization of NKT, a gene product related to the organic cation transporter family that is almost exclusively expressed in the kidney. Journal of Biological Chemistry, 272, 6471–6478.

    Article  CAS  PubMed  Google Scholar 

  11. Tsuda, M., Sekine, T., Takeda, M., Cha, S. H., Kanai, Y., Kimura, M., et al. (1999). Transport of ochratoxin A by renal multispecific organic anion transporter 1. Journal of Pharmacology and Experimental Therapeutics, 289, 1301–1305.

    CAS  PubMed  Google Scholar 

  12. Zalups, R. K., & Ahmad, S. (2005). Handling of cysteine S-conjugates of methylmercury in MDCK cells expressing human OAT1. Kidney International, 68, 1684–1699.

    Article  CAS  PubMed  Google Scholar 

  13. Eraly, S. A., Vallon, V., Vaughn, D. A., Gangoiti, J. A., Richter, K., Nagle, M., et al. (2006). Decreased renal organic anion secretion and plasma accumulation of endogenous organic anions in OAT1 knock-out mice. Journal of Biological Chemistry, 281, 5072–5083.

    Article  CAS  PubMed  Google Scholar 

  14. Vallon, V., Rieg, T., Ahn, S. Y., Wu, W., Eraly, S. A., & Nigam, S. K. (2008). Overlapping in vitro and in vivo specificities of the organic anion transporters OAT1 and OAT3 for loop and thiazide diuretics. American Journal of Physiology - Renal Physiology, 294, F867–F873.

    Article  CAS  PubMed  Google Scholar 

  15. Di Giusto, G., Anzai, N., Ruiz, M. L., Endou, H., & Torres, A. M. (2009). Expression and function of Oat1 and Oat3 in rat kidney exposed to mercuric chloride. Archives of Toxicology, 83, 887–897.

    Article  CAS  PubMed  Google Scholar 

  16. Sweet, D. H. (2005). Organic anion transporter (Slc22a) family members as mediators of toxicity. Toxicology and Applied Pharmacology, 204, 198–215.

    Article  CAS  PubMed  Google Scholar 

  17. Sauvant, C., Silbernagl, S., & Gekle, M. (1998). Exposure to ochratoxin A impairs organic anion transport in proximal-tubule-derived opossum kidney cells. Journal of Pharmacology and Experimental Therapeutics, 287, 13–20.

    CAS  PubMed  Google Scholar 

  18. Jung, K. Y., Takeda, M., Kim, D. K., Tojo, A., Narikawa, S., Yoo, B. S., et al. (2001). Characterization of ochratoxin A transport by human organic anion transporters. Life Sciences, 69, 2123–2135.

    Article  CAS  PubMed  Google Scholar 

  19. Burckhardt, B. C., & Burckhardt, G. (2003). Transport of organic anions across the basolateral membrane of proximal tubule cells. Reviews of Physiology Biochemistry and Pharmacology, 146, 95–158.

    Article  CAS  Google Scholar 

  20. Zlender, V., Breljak, D., Ljubojevic, M., Flajs, D., Balen, D., Brzica, H., et al. (2009). Low doses of ochratoxin A upregulate the protein expression of organic anion transporters Oat1, Oat2, Oat3 and Oat5 in rat kidney cortex. Toxicology and Applied Pharmacology, 239, 284–296.

    Article  CAS  PubMed  Google Scholar 

  21. Nagle, M. A., Truong, D. M., Dnyanmote, A. V., Eraly, S. A., Wu, W., & Nigam, S. K. (2010). Analysis of 3-dimensional systems for developing and mature kidney clarifies the role of OAT1 and OAT3 in antiviral handling. Journal of Biological Chemistry, 2010(286), 243–251.

    Google Scholar 

  22. Truong, D. M., Kaler, G., Khandelwal, A., Swaan, P. W., & Nigam, S. K. (2008). Multi-level analysis of organic anion transporters 1, 3, and 6 reveals major differences in structural determinants of antiviral discrimination. Journal of Biological Chemistry, 283, 8654–8663.

    Article  CAS  PubMed  Google Scholar 

  23. Chen, Y. J., Pornillos, O., Lieu, S., Ma, C., Chen, A. P., & Chang, G. (2007). X-ray structure of EmrE supports dual topology model. Proceedings of the National Academy of Sciences of the United States of America, 104, 18999–19004.

    Article  CAS  PubMed  Google Scholar 

  24. Lemieux, M. J. (2007). Eukaryotic major facilitator superfamily transporter modeling based on the prokaryotic GlpT crystal structure. Molecular Membrane Biology, 24, 333–341.

    Article  CAS  PubMed  Google Scholar 

  25. Perry, J. L., Dembla-Rajpal, N., Hall, L. A., & Pritchard, J. B. (2006). A three-dimensional model of human organic anion transporter 1: Aromatic amino acids required for substrate transport. Journal of Biological Chemistry, 281, 38071–38079.

    Article  CAS  PubMed  Google Scholar 

  26. Tsigelny, I. F., Greenberg, J., Kouznetsova, V., & Nigam, S. K. (2008). Modeling of glycerol-3-phosphate transporter suggests a potential ‘tilt’ mechanism involved in its function. Journal of Bioinformatics and Computational Biology, 6, 885–904.

    Article  CAS  PubMed  Google Scholar 

  27. Tsigelny, I., Sharikov, Y., & Ten Eyck, L. F. (2002). Hidden Markov models-based system (HMMSPECTR) for detecting structural homologies on the basis of sequential information. Protein Engineering, 15, 347–352.

    Article  CAS  PubMed  Google Scholar 

  28. Fujita, T., Brown, C., Carlson, E. J., Taylor, T., de la Cruz, M., Johns, S. J., et al. (2005). Functional analysis of polymorphisms in the organic anion transporter, SLC22A6 (OAT1). Pharmacogenetics and Genomics, 15, 201–209.

    Article  CAS  PubMed  Google Scholar 

  29. Humphrey, W., Dalke, A., & Schulten, K. (1996). VMD: Visual molecular dynamics. Journal of Molecular Graphics, 14(33–38), 27–38.

    Google Scholar 

  30. Hess, B., Kutzner, C., Van Der Spoel, D., & Lindahl, E. (2008). GROMACS4: Algorithms for highly efficient, load-balanced, and scalable molecular simulation. Journal of Chemical Theory and Computation, 4, 435–447.

    Article  CAS  Google Scholar 

  31. Oostenbrink, C., Soares, T. A., van der Vegt, N. F., & van Gunsteren, W. F. (2005). Validation of the 53A6 GROMOS force field. European Biophysics Journal, 34, 273–284.

    Article  CAS  PubMed  Google Scholar 

  32. Oostenbrink, C., Villa, A., Mark, A. E., & van Gunsteren, W. F. (2004). A biomolecular force field based on the free enthalpy of hydration and solvation: The GROMOS force-field parameter sets 53A5 and 53A6. Journal of Computational Chemistry, 25, 1656–1676.

    Article  CAS  PubMed  Google Scholar 

  33. Hess, B., Bekker, H., Berendsen, H. J. C., & Fraaije, J. G. E. M. (1997). LINCS: A linear constraint solver for molecular simulations. Journal of Computational Chemistry, 18, 1463–1472.

    Article  CAS  Google Scholar 

  34. Barrett, C. P., & Noble, M. E. (2005). Dynamite extended: Two new services to simplify protein dynamic analysis. Bioinformatics, 21, 3174–3175.

    Article  CAS  PubMed  Google Scholar 

  35. Lu, R., Chan, B. S., & Schuster, V. L. (1999). Cloning of the human kidney PAH transporter: Narrow substrate specificity and regulation by protein kinase C. American Journal of Physiology, 276, F295–F303.

    CAS  PubMed  Google Scholar 

  36. Race, J. E., Grassl, S. M., Williams, W. J., & Holtzman, E. J. (1999). Molecular cloning and characterization of two novel human renal organic anion transporters (hOAT1 and hOAT3). Biochemical and Biophysical Research Communications, 255, 508–514.

    Article  CAS  PubMed  Google Scholar 

  37. Lopez-Nieto, C. E., & Nigam, S. K. (1996). Selective amplification of protein-coding regions of large sets of genes using statistically designed primer sets. Nature Biotechnology, 14, 857–861.

    Article  CAS  PubMed  Google Scholar 

  38. Eraly, S. A., Blantz, R. C., Bhatnagar, V., & Nigam, S. K. (2003). Novel aspects of renal organic anion transporters. Current Opinion in Nephrology and Hypertension, 12, 551–558.

    Article  CAS  PubMed  Google Scholar 

  39. Eraly, S. A., Bush, K. T., Sampogna, R. V., Bhatnagar, V., & Nigam, S. K. (2004). The molecular pharmacology of organic anion transporters: From DNA to FDA? Molecular Pharmacology, 65, 479–487.

    Article  CAS  PubMed  Google Scholar 

  40. You, G. (2002). Structure, function, and regulation of renal organic anion transporters. Medicinal Research Reviews, 22, 602–616.

    Article  CAS  PubMed  Google Scholar 

  41. You, G. (2004). The role of organic ion transporters in drug disposition: An update. Current Drug Metabolism, 5, 55–62.

    Article  CAS  PubMed  Google Scholar 

  42. Zhou, F., & You, G. (2007). Molecular insights into the structure–function relationship of organic anion transporters OATs. Pharmaceutical Research, 24, 28–36.

    Article  PubMed  Google Scholar 

  43. Ahn, S. Y., Eraly, S. A., Tsigelny, I., & Nigam, S. K. (2009). Interaction of organic cations with organic anion transporters. Journal of Biological Chemistry, 284, 31422–31430.

    Article  CAS  PubMed  Google Scholar 

  44. Ahn, S. Y., & Nigam, S. K. (2009). Toward a systems level understanding of organic anion and other multispecific drug transporters: A remote sensing and signaling hypothesis. Molecular Pharmacology, 76, 481–490.

    Article  CAS  PubMed  Google Scholar 

  45. Kaler, G., Truong, D. M., Khandelwal, A., Nagle, M., Eraly, S. A., Swaan, P. W., et al. (2007). Structural variation governs substrate specificity for organic anion transporter (OAT) homologs. Potential remote sensing by OAT family members. Journal of Biological Chemistry, 282, 23841–23853.

    Article  CAS  PubMed  Google Scholar 

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Acknowledgments

We gratefully acknowledge support from the following NIH grants: NS062156, AI057695, GM 088824, and manuscript preparation support by Erin Richard.

Author information

Authors and Affiliations

  1. Department of Neurosciences, University of California, San Diego, La Jolla, CA, 92093, USA

    Igor F. Tsigelny & Yuriy Sharikov

  2. Department of Family and Preventative Medicine, University of California, San Diego, La Jolla, CA, 92093, USA

    Vibha Bhatnagar

  3. Department of Pediatrics, University of California, San Diego, La Jolla, CA, 92093, USA

    Valentina L. Kouznetsova & Sanjay K. Nigam

  4. Department of Medicine, University of California, San Diego, La Jolla, CA, 92093, USA

    Sanjay K. Nigam

  5. Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA, 92093, USA

    Sanjay K. Nigam

  6. Department of Bioengineering, University of California, San Diego, La Jolla, CA, 92093, USA

    Sanjay K. Nigam

  7. San Diego Supercomputer Center, University of California, San Diego, La Jolla, CA, 92093, USA

    Igor F. Tsigelny & Yuriy Sharikov

  8. Health Services Research and Development, VA San Diego Health Care System, San Diego, CA, 92161, USA

    Vibha Bhatnagar

  9. Enamine Ltd., 01103, Kiev, Ukraine

    Dmytro Kovalskyy

  10. ChemBio Center, Taras Shevchenko National University of Kyiv, 01601, Kyiv, Ukraine

    Dmytro Kovalskyy

  11. Faculty of Radiophysics, Taras Shevchenko National University of Kyiv, 01601, Kyiv, Ukraine

    Oleksii Balinskyi

  12. Institute of Molecular Biology and Genetics, The National Academy of Sciences, 03680, Kyiv, Ukraine

    Dmytro Kovalskyy

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  1. Igor F. Tsigelny
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  2. Dmytro Kovalskyy
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Correspondence to Igor F. Tsigelny.

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Tsigelny, I.F., Kovalskyy, D., Kouznetsova, V.L. et al. Conformational Changes of the Multispecific Transporter Organic Anion Transporter 1 (OAT1/SLC22A6) Suggests a Molecular Mechanism for Initial Stages of Drug and Metabolite Transport. Cell Biochem Biophys 61, 251–259 (2011). https://doi.org/10.1007/s12013-011-9191-7

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