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The cells and logic for mammalian sour taste detection


Mammals taste many compounds yet use a sensory palette consisting of only five basic taste modalities: sweet, bitter, sour, salty and umami (the taste of monosodium glutamate)1,2. Although this repertoire may seem modest, it provides animals with critical information about the nature and quality of food. Sour taste detection functions as an important sensory input to warn against the ingestion of acidic (for example, spoiled or unripe) food sources1,2,3. We have used a combination of bioinformatics, genetic and functional studies to identify PKD2L1, a polycystic-kidney-disease-like ion channel4, as a candidate mammalian sour taste sensor. In the tongue, PKD2L1 is expressed in a subset of taste receptor cells distinct from those responsible for sweet, bitter and umami taste. To examine the role of PKD2L1-expressing taste cells in vivo, we engineered mice with targeted genetic ablations of selected populations of taste receptor cells. Animals lacking PKD2L1-expressing cells are completely devoid of taste responses to sour stimuli. Notably, responses to all other tastants remained unaffected, proving that the segregation of taste qualities even extends to ionic stimuli. Our results now establish independent cellular substrates for four of the five basic taste modalities, and support a comprehensive labelled-line mode of taste coding at the periphery5,6,7,8,9,10. Notably, PKD2L1 is also expressed in specific neurons surrounding the central canal of the spinal cord. Here we demonstrate that these PKD2L1-expressing neurons send projections to the central canal, and selectively trigger action potentials in response to decreases in extracellular pH. We propose that these cells correspond to the long-sought components of the cerebrospinal fluid chemosensory system11. Taken together, our results suggest a common basis for acid sensing in disparate physiological settings.

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Figure 1: PKD2L1 is expressed in a novel population of TRCs.
Figure 2: PKD2L1-expressing TRCs are the mediators of sour taste.
Figure 3: PKD2L1 is expressed in neurons contacting the central canal of the spinal cord.
Figure 4: PKD2L1-expressing neurons of the central canal fire action potentials in response to pH stimulation.


  1. Lindemann, B. Receptors and transduction in taste. Nature 413, 219–225 (2001)

    Article  ADS  CAS  Google Scholar 

  2. Kinnamon, S. C. & Margolskee, R. F. Mechanisms of taste transduction. Curr. Opin. Neurobiol. 6, 506–513 (1996)

    Article  CAS  Google Scholar 

  3. DeSimone, J. A., Lyall, V., Heck, G. L. & Feldman, G. M. Acid detection by taste receptor cells. Respir. Physiol. 129, 231–245 (2001)

    Article  CAS  Google Scholar 

  4. Wu, G. et al. Identification of PKD2L, a human PKD2-related gene: tissue-specific expression and mapping to chromosome 10q25. Genomics 54, 564–568 (1998)

    Article  CAS  Google Scholar 

  5. Adler, E. et al. A novel family of mammalian taste receptors. Cell 100, 693–702 (2000)

    Article  CAS  Google Scholar 

  6. Nelson, G. et al. Mammalian sweet taste receptors. Cell 106, 381–390 (2001)

    Article  CAS  Google Scholar 

  7. Nelson, G. et al. An amino-acid taste receptor. Nature 416, 199–202 (2002)

    Article  ADS  CAS  Google Scholar 

  8. Zhang, Y. et al. Coding of sweet, bitter, and umami tastes: different receptor cells sharing similar signaling pathways. Cell 112, 293–301 (2003)

    Article  CAS  Google Scholar 

  9. Zhao, G. Q. et al. The receptors for mammalian sweet and umami taste. Cell 115, 255–266 (2003)

    Article  CAS  Google Scholar 

  10. Mueller, K. L. et al. The receptors and coding logic for bitter taste. Nature 434, 225–229 (2005)

    Article  ADS  CAS  Google Scholar 

  11. Vigh, B. et al. The system of cerebrospinal fluid-contacting neurons. Its supposed role in the nonsynaptic signal transmission of the brain. Histol. Histopathol. 19, 607–628 (2004)

    CAS  PubMed  Google Scholar 

  12. Lyall, V. et al. The mammalian amiloride-insensitive non-specific salt taste receptor is a vanilloid receptor-1 variant. J. Physiol. (Lond.) 558, 147–159 (2004)

    Article  CAS  Google Scholar 

  13. Vinnikova, A. K. et al. Na+-H+ exchange activity in taste receptor cells. J. Neurophysiol. 91, 1297–1313 (2004)

    Article  CAS  Google Scholar 

  14. Matsunami, H., Montmayeur, J. P. & Buck, L. B. A family of candidate taste receptors in human and mouse. Nature 404, 601–604 (2000)

    Article  ADS  CAS  Google Scholar 

  15. Chandrashekar, J. et al. T2Rs function as bitter taste receptors. Cell 100, 703–711 (2000)

    Article  CAS  Google Scholar 

  16. Li, X. et al. Human receptors for sweet and umami taste. Proc. Natl Acad. Sci. USA 99, 4692–4696 (2002)

    Article  ADS  CAS  Google Scholar 

  17. Nauli, S. M. et al. Polycystins 1 and 2 mediate mechanosensation in the primary cilium of kidney cells. Nature Genet. 33, 129–137 (2003)

    Article  CAS  Google Scholar 

  18. Delmas, P. Polycystins: polymodal receptor/ion-channel cellular sensors. Pflugers Arch. 451, 264–276 (2005)

    Article  CAS  Google Scholar 

  19. Clapham, D. E. TRP channels as cellular sensors. Nature 426, 517–524 (2003)

    Article  ADS  CAS  Google Scholar 

  20. Murakami, M. et al. Genomic organization and functional analysis of murine PKD2L1. J. Biol. Chem. 280, 5626–5635 (2005)

    Article  CAS  Google Scholar 

  21. LopezJimenez, N. D. et al. Two members of the TRPP family of ion channels, Pkd1l3 and Pkd2l1, are co-expressed in a subset of taste receptor cells. J. Neurochem. 98, 68–77 (2006)

    Article  CAS  Google Scholar 

  22. Hoon, M. A. et al. Putative mammalian taste receptors: a class of taste-specific GPCRs with distinct topographic selectivity. Cell 96, 541–551 (1999)

    Article  CAS  Google Scholar 

  23. Collier, R. J. Diphtheria toxin: mode of action and structure. Bacteriol. Rev. 39, 54–85 (1975)

    CAS  PubMed  PubMed Central  Google Scholar 

  24. Brockschnieder, D. et al. Cell depletion due to diphtheria toxin fragment A after Cre-mediated recombination. Mol. Cell. Biol. 24, 7636–7642 (2004)

    Article  CAS  Google Scholar 

  25. Perez, C. A. et al. A transient receptor potential channel expressed in taste receptor cells. Nature Neurosci. 5, 1169–1176 (2002)

    Article  CAS  Google Scholar 

  26. Lahiri, S. & Forster, R. E. II CO2/H+ sensing: peripheral and central chemoreception. Int. J. Biochem. Cell Biol. 35, 1413–1435 (2003)

    Article  CAS  Google Scholar 

  27. Richerson, G. B., Wang, W., Hodges, M. R., Dohle, C. I. & Diez-Sampedro, A. Homing in on the specific phenotype(s) of central respiratory chemoreceptors. Exp. Physiol. 90, 259–266, 266–269 (2005)

    Article  CAS  Google Scholar 

  28. Gosgnach, S. et al. V1 spinal neurons regulate the speed of vertebrate locomotor outputs. Nature 440, 215–219 (2006)

    Article  ADS  CAS  Google Scholar 

  29. Lee, E. C. et al. A highly efficient Escherichia coli-based chromosome engineering system adapted for recombinogenic targeting and subcloning of BAC DNA. Genomics 73, 56–65 (2001)

    Article  CAS  Google Scholar 

  30. Novak, A., Guo, C., Yang, W., Nagy, A. & Lobe, C. G. Z/EG, a double reporter mouse line that expresses enhanced green fluorescent protein upon Cre-mediated excision. Genesis 28, 147–155 (2000)

    Article  CAS  Google Scholar 

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We thank L. Feng for help with expression studies, A. Becker for generation of antibodies, D. Cowan for sequencing, and K. Briedis for bioinformatics. We especially thank Y. Zhang for introducing us to the spinal cord slice preparation, and superb technical guidance and help with equipment and animals. We thank members of the Zuker laboratory for valuable comments. This research was supported in part by a grant from the National Institute on Deafness and Other Communication Disorders to C.S.Z. and the intramural research program of the NIH, NIDCR (N.J.P.R.). X.C. is a fellow of the HFS program and D.T. is supported by an Emmy-Noether grant of the Deutsche Forschungsgemeinschaft. C.S.Z. is an investigator of the Howard Hughes Medical Institute.

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Correspondence to Charles S. Zuker.

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Huang, A., Chen, X., Hoon, M. et al. The cells and logic for mammalian sour taste detection. Nature 442, 934–938 (2006).

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