Advertisement
JBC

HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
 QUICK SEARCH:   [advanced]


     


Originally published In Press as doi:10.1074/jbc.M409454200 on May 3, 2005

J. Biol. Chem., Vol. 280, Issue 27, 25436-25449, July 8, 2005
This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow All Versions of this Article:
280/27/25436    most recent
M409454200v1
Right arrow Submit a Letter to Editor
Right arrow Alert me when this article is cited
Right arrow Alert me when eLetters are posted
Right arrow Alert me if a correction is posted
Right arrow Citation Map
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrowRequest Permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Smith, K. M.
Right arrow Articles by Young, J. D.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Smith, K. M.
Right arrow Articles by Young, J. D.
Social Bookmarking
 Add to CiteULike   Add to Complore   Add to Connotea   Add to Del.icio.us   Add to Digg   Add to Reddit   Add to Technorati  
What's this?

The Broadly Selective Human Na+/Nucleoside Cotransporter (hCNT3) Exhibits Novel Cation-coupled Nucleoside Transport Characteristics*

Kyla M. Smith{ddagger}§, Melissa D. Slugoski{ddagger}§, Shaun K. Loewen{ddagger}§, Amy M. L. Ng{ddagger}, Sylvia Y. M. Yao{ddagger}, Xing-Zhen Chen{ddagger}, Edward Karpinski{ddagger}, Carol E. Cass||**{ddagger}{ddagger}, Stephen A. Baldwin§§, and James D. Young{ddagger}¶¶

From the Membrane Protein Research Group, Departments of{ddagger} Physiology and|| Oncology, University of Alberta, and the** Cross Cancer Institute, Edmonton, Alberta T6G 2H7, Canada and the §§School of Biochemistry and Microbiology, University of Leeds, Leeds LS2 9JT, United Kingdom

The concentrative nucleoside transporter (CNT) protein family in humans is represented by three members, hCNT1, hCNT2, and hCNT3. hCNT3, a Na+/nucleoside symporter, transports a broad range of physiological purine and pyrimidine nucleosides as well as anticancer and antiviral nucleoside drugs, and belongs to a different CNT subfamily than hCNT1/2. H+-dependent Escherichia coli NupC and Candida albicans CaCNT are also CNT family members. The present study utilized heterologous expression in Xenopus oocytes to investigate the specificity, mechanism, energetics, and structural basis of hCNT3 cation coupling. hCNT3 exhibited uniquely broad cation interactions with Na+, H+, and Li+ not shared by Na+-coupled hCNT1/2 or H+-coupled NupC/CaCNT. Na+ and H+ activated hCNT3 through mechanisms to increase nucleoside apparent binding affinity. Direct and indirect methods demonstrated cation/nucleoside coupling stoichiometries of 2:1 in the presence of Na+ and both Na+ plus H+, but only 1:1 in the presence of H+ alone, suggesting that hCNT3 possesses two Na+-binding sites, only one of which is shared by H+. The H+-coupled hCNT3 did not transport guanosine or 3'-azido-3'-deoxythymidine and 2',3'-dideoxycytidine, demonstrating that Na+- and H+-bound versions of hCNT3 have significantly different conformations of the nucleoside binding pocket and/or translocation channel. Chimeric studies between hCNT1 and hCNT3 located hCNT3-specific cation interactions to the C-terminal half of hCNT3, setting the stage for site-directed mutagenesis experiments to identify the residues involved.


Received for publication, August 17, 2004 , and in revised form, March 24, 2005.

* This work was supported in part by the National Cancer Institute of Canada, with funds from the Canadian Cancer Society, the Alberta Cancer Board, the Heart and Stroke Foundation, Canada, and the Medical Research Council, UK. The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked "advertisement" in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.

§ These authors contributed equally to this work.

Funded by Studentships from the Alberta Heritage Foundation for Medical Research.

{ddagger}{ddagger} A Canada Research Chair in Oncology.

¶¶ A Heritage Scientist of the Alberta Heritage Foundation for Medical Research. To whom correspondence should be addressed: Dept. of Physiology, 7-55 Medical Sciences Bldg., University of Alberta, Edmonton, Alberta T6G 2H7, Canada. Tel.: 780-492-5895; Fax: 780-492-7566; E-mail: james.young{at}ualberta.ca.


Add to CiteULike CiteULike   Add to Complore Complore   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us   Add to Digg Digg   Add to Reddit Reddit   Add to Technorati Technorati    What's this?


This article has been cited by other articles:


Home page
J. Biol. Chem.Home page
M. D. Slugoski, K. M. Smith, A. M. L. Ng, S. Y. M. Yao, E. Karpinski, C. E. Cass, S. A. Baldwin, and J. D. Young
Conserved Glutamate Residues Glu-343 and Glu-519 Provide Mechanistic Insights into Cation/Nucleoside Cotransport by Human Concentrative Nucleoside Transporter hCNT3
J. Biol. Chem., June 19, 2009; 284(25): 17266 - 17280.
[Abstract] [Full Text] [PDF]


Home page
J. Biol. Chem.Home page
M. D. Slugoski, A. M. L. Ng, S. Y. M. Yao, C. C. Lin, R. Mulinta, C. E. Cass, S. A. Baldwin, and J. D. Young
Substituted Cysteine Accessibility Method Analysis of Human Concentrative Nucleoside Transporter hCNT3 Reveals a Novel Discontinuous Region of Functional Importance within the CNT Family Motif (G/A)XKX3NEFVA(Y/M/F)
J. Biol. Chem., June 19, 2009; 284(25): 17281 - 17292.
[Abstract] [Full Text] [PDF]


Home page
FASEB J.Home page
E. Errasti-Murugarren, M. Molina-Arcas, F. J. Casado, and M. Pastor-Anglada
A splice variant of the SLC28A3 gene encodes a novel human concentrative nucleoside transporter-3 (hCNT3) protein localized in the endoplasmic reticulum
FASEB J, January 1, 2009; 23(1): 172 - 182.
[Abstract] [Full Text] [PDF]


Home page
Mol. Pharmacol.Home page
R. J. Paproski, A. M. L. Ng, S. Y. M. Yao, K. Graham, J. D. Young, and C. E. Cass
The Role of Human Nucleoside Transporters in Uptake of 3'-Deoxy-3'-fluorothymidine
Mol. Pharmacol., November 1, 2008; 74(5): 1372 - 1380.
[Abstract] [Full Text] [PDF]


Home page
J. Biol. Chem.Home page
M. D. Slugoski, K. M. Smith, R. Mulinta, A. M. L. Ng, S. Y. M. Yao, E. L. Morrison, Q. O. T. Lee, J. Zhang, E. Karpinski, C. E. Cass, et al.
A Conformationally Mobile Cysteine Residue (Cys-561) Modulates Na+ and H+ Activation of Human CNT3
J. Biol. Chem., September 5, 2008; 283(36): 24922 - 24934.
[Abstract] [Full Text] [PDF]


Home page
J. Biol. Chem.Home page
M. D. Slugoski, A. M. L. Ng, S. Y. M. Yao, K. M. Smith, C. C. Lin, J. Zhang, E. Karpinski, C. E. Cass, S. A. Baldwin, and J. D. Young
A Proton-mediated Conformational Shift Identifies a Mobile Pore-lining Cysteine Residue (Cys-561) in Human Concentrative Nucleoside Transporter 3
J. Biol. Chem., March 28, 2008; 283(13): 8496 - 8507.
[Abstract] [Full Text] [PDF]


Home page
Mol. Pharmacol.Home page
E. Errasti-Murugarren, P. Cano-Soldado, M. Pastor-Anglada, and F. J. Casado
Functional Characterization of a Nucleoside-Derived Drug Transporter Variant (hCNT3C602R) Showing Altered Sodium-Binding Capacity
Mol. Pharmacol., February 1, 2008; 73(2): 379 - 386.
[Abstract] [Full Text] [PDF]


Home page
J. Biol. Chem.Home page
S. Y. M. Yao, A. M. L. Ng, M. D. Slugoski, K. M. Smith, R. Mulinta, E. Karpinski, C. E. Cass, S. A. Baldwin, and J. D. Young
Conserved Glutamate Residues Are Critically Involved in Na+/Nucleoside Cotransport by Human Concentrative Nucleoside Transporter 1 (hCNT1)
J. Biol. Chem., October 19, 2007; 282(42): 30607 - 30617.
[Abstract] [Full Text] [PDF]


Home page
Am. J. Physiol. Renal Physiol.Home page
V. L. Damaraju, A. N. Elwi, C. Hunter, P. Carpenter, C. Santos, G. M. Barron, X. Sun, S. A. Baldwin, J. D. Young, J. R. Mackey, et al.
Localization of broadly selective equilibrative and concentrative nucleoside transporters, hENT1 and hCNT3, in human kidney
Am J Physiol Renal Physiol, July 1, 2007; 293(1): F200 - F211.
[Abstract] [Full Text] [PDF]


Home page
Am. J. Physiol. Cell Physiol.Home page
I. M. Larrayoz, A. Fernandez-Nistal, A. Garces, E. Gorraitz, and M. P. Lostao
Characterization of the rat Na+/nucleoside cotransporter 2 and transport of nucleoside-derived drugs using electrophysiological methods
Am J Physiol Cell Physiol, December 1, 2006; 291(6): C1395 - C1404.
[Abstract] [Full Text] [PDF]


Home page
Mol. Pharmacol.Home page
M. L. Clarke, V. L. Damaraju, J. Zhang, D. Mowles, T. Tackaberry, T. Lang, K. M. Smith, J. D. Young, B. Tomkinson, and C. E. Cass
The Role of Human Nucleoside Transporters in Cellular Uptake of 4'-Thio-beta-D-arabinofuranosylcytosine and beta-D-Arabinosylcytosine
Mol. Pharmacol., July 1, 2006; 70(1): 303 - 310.
[Abstract] [Full Text] [PDF]


Home page
Mol. Pharmacol.Home page
H. Hu, C. J. Endres, C. Chang, N. S. Umapathy, E.-W. Lee, Y.-J. Fei, S. Itagaki, P. W. Swaan, V. Ganapathy, and J. D. Unadkat
Electrophysiological Characterization and Modeling of the Structure Activity Relationship of the Human Concentrative Nucleoside Transporter 3 (hCNT3)
Mol. Pharmacol., May 1, 2006; 69(5): 1542 - 1553.
[Abstract] [Full Text] [PDF]




HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
 All ASBMB Journals   Molecular and Cellular Proteomics 
 Journal of Lipid Research   ASBMB Today 
Copyright © 2005 by the American Society for Biochemistry and Molecular Biology.
Advertisement
spacer
Advertisement
Advertisement