Dr. Ana M. Pajor

Transporters

Ana M. Pajor, Ph.D.

Professor
Skaggs School of Pharmacy and Pharmaceutical Sciences
Telephone: (858) 822-7806
Email: apajor@ucsd.edu

Research Summary: Transporters

The main focus of the Pajor lab is to understand the mechanism of sodium-coupled transporters, particularly the Na+/dicarboxylate cotransporters (NaDC) from the SLC13 family. NaDC1, the low affinity transporter, is found in the kidney and small intestine where it is involved in absorbing citric acid cycle intermediates such as succinate, citrate and α-ketoglutarate into the cells. The transport activity of NaDC1 may affect many processes in the body including the development of kidney stones, regulation of blood pressure, secretion of organic anion drugs and xenobiotics via the organic anion transporters (OATs), and determination of lifespan. Our main interest is the relationship between structure and function in NaDC1 (and its bacterial homolog SdcS), and the identification of substrate and cation binding sites. Recent studies include characterization of a new inhibitor of NaDC1, which may serve as a prodrug for further development.

Academic Achievements

Education: B.Sc. Biology, Ottawa (1978); M.Sc. Biology, Ottawa (1982); Visiting student, Karolinska Institute (1982-83); Ph.D. Physiology, Arizona (1988); Postdoctoral training, UCLA (1988-91).
Awards and Honors: NIH Research Career Development Award (1996-01); Executive Leadership in Academic Medicine Fellow (2003-04); J. Biol. Chem. Editorial Board (2000-05).
Leadership Experience: Chair ad interim, Department of Physiology and Molecular Biophysics, University of Texas Medical Branch, Galveston, TX (2003-04).

Teaching

* Organ Physiology (SOM 206/SPPS 243)
* Pharmacogenomics (SPPS 219).
* Principles of Pharmacology (SOM/SPPS 217A.
* Concepts in Pharmacy Practice (SPPS 202A).
* Ethics in Scientific Research (BIOM/Pharm 219).

Key Contributions to Pharmaceutical Sciences

* Expression cloning of NaDC1.
* Identification of other SLC13 family members, including NaDC3, SdcS, hNaS1.
* Identification of renal SGLT2.
* Identification of NaDC1 inhibitor.

Selected Recent Publications

(PubMed List)
Pajor et al (2006). Molecular properties of the SLC13 family of dicarboxylate and sulfate transporters: an update. Pflugers Archiv, 451:597-605.
Pajor et al. (2007). Inhibition of the Na+/dicarboxylate cotransporter by anthranilic acid derivatives. Mol. Pharm. 72:1-7.
Weerachayaphorn et al. (2007). Sodium-dependent extracellular accessibility of Lys-84 in the sodium/dicarboxylate cotransporter. J. Biol. Chem. 282:20213-20220.
Pajor et al. (2008). Inhibitor binding in the human renal low- and high-affinity Na+/glucose cotransporters. Journal of Pharmacology and Experimental Therapeutics. 324:985-991.
Joshi et al. (2009). Identification of conformationally sensitive amino acids in the Na+/dicarboxylate symporter (SdcS). Biochemistry 48:3017.

Potential Collaborative Programs with the Pharmaceutical Industry

* 25 years experience with sodium-coupled transporters for glucose, nucleosides, dicarboxylates, sulfate.
* Variety of experimental systems: mammalian cells in culture, Xenopus oocytes, E. coli, BacMam, radiotracer transport assay, two-electrode voltage clamp.