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Fawaz G. Haj

Fawaz G. Haj

  • Associate Professor, Department of Nutrition
  • Associate Professor, Department of Internal Medicine
  • Associate Nutritionist in Agricultural Experiment Station

3115 Meyer

(530) 752-3214



  • D.Phil., Physiology, Oxford University
  • M.Sc., Biomedical Sciences, Bradford University
  • B.Sc., Biology, American University of Beirut

Post Graduate Training

  • Postdoctoral Fellow, Harvard Medical School
  • Instructor in Medicine, Harvard Medical School
  • Visiting Scientist, European Molecular Biology Laboratory

Academic Appointments

  • Assistant Professor, Nutrition Department, University of California Davis, 2007-2011
  • Associate Professor, Nutrition Department, University of California Davis, 2011-present
  • Associate Professor, Internal Medicine Department, University of California Davis, 2012-present

Administrative Appointments

  • Director, Meyer Hall Animal Facility, University of California Davis, 2008-present
  • Co-Director, Metabolism and Endocrinology Core, National Mouse Metabolic Phenotyping Center, University of California Davis, 2011-present

Awards and Honors

  • Oxford University, Oxford Overseas Bursaries, 1997
  • Oxford University, Overseas Research Scholarship, 1997
  • Harvard University, Certificate of Excellence in Research, 2001
  • University of California Davis, Hellman Fellow, 2008

Oral presentations (last 3 years)


  • Division of Endocrinology, Diabetes and Metabolism, University of Miami, Miami, Florida, USA
  • School of Medicine, University of Miami, Miami, Florida, USA
  • Pre-Obesity Society Symposium, Orlando, Florida, USA
  • 9th International Conference on Protein Phosphatases, Tokyo, Japan
  • Department of Microbiology, Yokohama City University, Yokohama, Japan
  • EMBO conference on protein phosphatases, Vienna, Austria
  • Department of Biology, University of Copenhagen, Copenhagen, Denmark
  • Frontiers of Science, Engineering and Medicine Symposium, Kuwait Institute for Scientific Research, Kuwait City, Kuwait
  • Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan
  • Taiwan Society for Biochemistry and Molecular Biology, Taipei, Taiwan
  • Department of Biological Sciences, National University of Singapore, Singapore
  • Duke-National University of Singapore Graduate Medical School, Singapore


  • Comprehensive Cancer Center, University of California Davis, Sacramento, CA, USA
  • Department of Orthopedics, University of California Davis, Sacramento, CA, USA
  • Protein Phosphatases Conference, Silvertree, CO, USA
  • Department of Nutritional Biology and Toxicology, University of California Berkeley, CA, USA
  • Phosphatases in human disease conference, Melbourne, Australia
  • Garvan Institute, Sydney, Australia
  • International conference on obesity and weight management, Philadelphia, PA, USA


  • Division of Endocrinology, Diabetes and Metabolism, University of California Davis, Sacramento, CA
  • 10th International Conference on Protein Phosphatases and Diseases, Tokyo, Japan
  • Brain-Liver Interface Medicine Research Center, Kanazawa University, Kanazawa, Japan
  • Nutrition, Oxygen Biology and Medicine Conference, Paris, France           
  • Department of Molecular Cell Biology, University of Leuven, Belgium
  • VI International Conference on Polyphenols and Health, Buenos Aires, Argentina
  • Institute of Biomedical Investigation Alberto Sols, Madrid, Spain
  • Department of Physiology, University of Valencia, Valencia, Spain

Research Interests

Dr. Haj´s laboratory studies the role of tyrosine phosphorylation and dephosphorylation in cell signaling and disease. Research focuses on the function of protein-tyrosine phosphatases (PTPs) in regulating insulin signaling and how deregulation of these pathways leads to diseases such as obesity and type 2 diabetes. This is achieved through the combined use of biochemical, cellular and knockout mouse studies. Collectively, these approaches will enable the dissection of metabolic regulation at the cellular and organism levels.


Selected Publications

  • Bakke J, Bettaieb A, Nagata N, Matsuo K, Haj FG. Regulation of the SNARE-interacting protein Munc18c tyrosine phosphorylation in adipocytes by protein-tyrosine phosphatase 1B. Cell Commun Signal. 2013 Aug 12;11:57.  [PubMed]
  • Bettaieb A, Bakke J, Nagata N, Matsuo K, Xi Y, Liu S, AbouBechara D, Melhem R, Stanhope K, Cummings B, Graham J, Bremer A, Zhang S, Lyssiotis CA, Zhang ZY, Cantley LC, Havel PJ, Haj FG. Protein tyrosine phosphatase 1B regulates pyruvate kinase M2 tyrosine phosphorylation. J Biol Chem. 2013 Jun 14;288(24):17360-71. [PubMed]
  • Bettaieb A, Nagata N, AbouBechara D, Chahed S, Morisseau C, Hammock BD, Haj FG. Soluble epoxide hydrolase deficiency or inhibition attenuates diet-induced endoplasmic reticulum stress in liver and adipose tissue. J Biol Chem. 2013 May 17;288(20):14189-99. [PubMed]
  • Lackey DE, Lynch CJ, Olson KC, Mostaedi R, Ali M, Smith WH, Karpe F, Humphreys S, Bedinger DH, Dunn TN, Thomas AP, Oort PJ, Kieffer DA, Amin R, Bettaieb A, Haj FG, Permana P, Anthony TG, Adams SH.Regulation of adipose branched-chain amino acid catabolism enzyme expression and cross-adipose amino acid flux in human obesity. Am J Physiol Endocrinol Metab. 2013 Jun 1;304(11):E1175-87. [PubMed]
  • Cummings BP, Bettaieb A, Graham JL, Kim J, Ma F, Shibata N, Stanhope KL, Giulivi C, Hansen F, Jelsing J, Vrang N, Kowala M, Chouinard ML, Haj FG, Havel PJ. Bile-acid-mediated decrease in endoplasmic reticulum stress: a potential contributor to the metabolic benefits of ileal interposition surgery in UCD-T2DM rats. Dis Model Mech. 2013 Mar;6(2):443-56. [PubMed]
  • Bora Inceoglu, Karen Wagner, Jun Yang, Ahmed Bettaieb, Nils Schebb, Fawaz Haj, Bruce Hammock (2012). Augmentation of epoxygenated fatty acid levels rapidly reduce pain-related behavior without significantly altering acute glucose metabolism in a rat model of type I diabetes. Proceedings of the National Academy of Sciences, Jul 10;109(28):11390-5. [PubMed]
  • Bethany Cummings, Ahmed Bettaieb, James Graham, Kimber Stanhope, Mark Kowala, Fawaz Haj, Michael Chouinard, and Peter Havel (2012). Vertical sleeve gastrectomy improves glucose and lipid metabolism and delays diabetes onset in UCD-T2DM rats. Endocrinology, Aug;153(8):3620-32. [PubMed]
  • Naoto Nagata, Kosuke Matsuo, Ahmed Bettaieb, Jesse Bakke, Izumi Matsuo, James Graham, Yannan Xi, Siming Liu, Alexey Tomilov, Natalia Tomilova, Susan Gray, Dae Young Jung, Jon Ramsey, Jason Kim, Gino Cortopassi, Peter Havel and Fawaz Haj (2012). Hepatic Src Homology Phosphatase 2 regulates energy balance in mice. Endocrinology, Jul;153(7):3158-69. [PubMed]
  • Fawaz Haj, Ola Sabet, Ali Kinkhabwala, Sabine Wimmer-Kleikamp, Vassilis Roukos,Hong-Mei Han, Markus Grabenbauer, Martin Bierbaum, Claude Antony, Benjamin Neel, and Philippe Bastiaens (2012). Regulation of signaling at regions of cell-cell contact by endoplasmic reticulum-bound protein-tyrosine phosphatase 1B. PLoS One, 7(5):e36633. [PubMed]
  • Ahmed Bettaieb, Kosuke Matsuo, Shuo Wang, Izumi Matsuo, Ramzi Melhem, Antonis Koromilas and Fawaz Haj (2012). Protein tyrosine phosphatase 1B deficiency potentiates PERK/eIF2α signaling in brown adipocytes. PLoS One, 7(4):e34412. [PubMed]
  • Marcela Vazquez Prieto, Ahmed Bettaieb, Fawaz Haj, Cesar Fraga, Patricia Oteiza (2012). (-)-Epicatechin prevents TNFα-induced activation of signaling cascades leading to inflammation and insulin resistance in 3T3 adipocytes. Archives of Biochemistry and Biophysics, Nov 15; 527(2):113-8. [PubMed]
  • Bethany Cummings, Ahmed Bettaieb, James Graham, Kimber Stanhope, Riva Dill, Gregory Morton, Fawaz Haj and Peter Havel (2011). Subcutaneous administration of leptin normalizes fasting plasma glucose in obese type 2 diabetes UCD-T2DM rats. Proceedings of the National Academy of Sciences, August 30; 108(35):14670-5.  [PubMed]
  • Ayala Luria, Ahmed Bettaieb, Yannan Xi, Guang-Jong Shieh, Hsin-Chen Liu, Hiromi Inoue, Hsing-Ju Tsai, John Imig, Fawaz Haj and Bruce Hammock (2011). Soluble epoxide hydrolase deficiency alters pancreatic islet size and improves glucose homeostasis in a model of insulin resistance induced by high fat diet. Proceedings of the National Academy of Sciences, May 31;108(22):9038-43. [PubMed]
  • Ahmed Bettaieb, Kosuke Matsuo, Izumi Matsuo and Fawaz Haj (2011). Adipose-specific Src Homology Phosphatase 2 deficiency does not significantly alter systemic glucose homeostasis. Metabolism, Aug;60(8):1193-201.  [PubMed]
  • Kosuke Matsuo, Ahmed Bettaieb, Naoto Nagata, Izumi Matsuo and Fawaz Haj (2011). Regulation of brown fat adipogenesis by protein tyrosine phosphatase 1B. PLoS One, Jan 31;6(1):e16446. [PubMed]
  • Ahmed Bettaieb, Siming Liu, Yannan Xi, Naoto Nagata, Kosuke Matsuo, Izumi Matsuo, Samah Chahed, Jesse Bakke, Heike Keilhack, Tony Tiganis and Fawaz Haj (2011). Differential regulation of endoplasmic reticulum stress by protein tyrosine phosphatase 1B and T cell protein tyrosine phosphatase. Journal of Biological Chemistry, Mar 18;286(11):9225-35.  [PubMed]
  • Eva Nievergall, Peter Janes, Carolin Stegmayer, Mary Vail, Fawaz Haj, Shyh Wei Teng, Benajmin Neel, Philippe Bastiaens and Martin Lackman (2010). Protein-Tyrosine Phosphatase 1B regulates Eph receptor function and trafficking. Journal of Cell Biology, Dec 13; 191(6):1189-203. [PubMed]
  • Kosuke Matsuo, Mirela Delibegovic, Izumi Matsuo, Naoto Nagata, Siming Liu, Ahmed Bettaieb, Yannan Xi, Kazu Araki, Wentien Yang, Barbara Kahn, Benjamin Neel and Fawaz Haj (2010). Altered glucose homeostasis in mice with liver-specific deletion of Src Homology Phosphatase 2. Journal of Biological Chemistry, Dec 17, 285(51):39750-8. [PubMed]
  • Xue B, Pulinilkunnil T, Murano I, Bence KK, He H, Minokoshi Y, Asakura K, Lee A, Haj F, Furukawa N, Catalano KJ, Delibegovic M, Balschi JA, Cinti S, Neel BG, Kahn BB (2009). Neuronal protein tyrosine phosphatase 1B deficiency results in inhibition of hypothalamic AMPK and isoform-specific activation of AMPK in peripheral tissues. Mol Cell Biol. Aug;29(16):4563-73. [PubMed]
  • Shrikrishna Dadke, Sophie Cotteret, Shu-Chin Yip, Zahara Jaffer, Fawaz Haj, Alexey Ivanov, Frank Rauscher III, Ke Shuai, Tony Ng, Benjamin Neel, and Jonathan Chernoff (2007).  Regulation of protein-tyrosine phosphatase 1B through sumoylation.  Nature Cell Biology.  Jan, 9(1): 80-85. [PubMed]
  • Elena Arias-Salgado, Fawaz Haj, Christophe Dubois, Barry Moran, Ana Kasirer-Friede, Barbara Furie, Bruce Furie, Benjamin Neel and Sanford Shattil (2005).  PTP-1B is an essential positive regulator of platelet integrin signaling.  Journal of Cell Biology.  Aug 29,170 (5): 837-45. [PubMed]
  • Fawaz Haj, Janice Zabolotny, Young-Bum Kim, Barbara Kahn and Benjamin Neel (2005).  Liver-specific re-expression of protein-tyrosine phosphatase 1B reverses insulin sensitivity in PTP1B knockout mice.  Journal of Biological Chemistry.  Apr 15, 280 (15): 15038-46. [PubMed]
  • Sandra Galic, Christine Hauser, Barbara Kahn, Fawaz Haj, Benjamin Neel, Nicholas Tonks, and Tony Tiganis (2005).  Coordinated regulation of insulin signaling by the protein tyrosine phosphatases PTP1B and TCPTP.  Molecular and Cellular Biology.  Jan, 25 (2): 819-29. [PubMed]
  • Janice Zabolotny, Fawaz Haj, Jason Kim, Young-Bum Kim, Gerald Shulman, Barbara Kahn and Benjamin Neel (2004).  Transgenic overexpression of protein-tyrosine phosphatase 1B in muscle causes insulin resistance, but overexpression with leukocyte antigen-related phosphatase does not additively impair insulin action.  Journal of Biological Chemistry.  Jun 4, 279 (23): 24844-51. [PubMed]
  • Camilla Persson, Catrine Svenhed, Annie Bourdeau, Michel Tremblay, Boyka Markova, Frank Bhmer, Fawaz Haj, Benjamin Neel, Carl-Henrik Heldin, Lars Rnnstrand, Arne stman and Carina Hellberg (2004).  Site-selective regulation of platelet growth factor b receptor tyrosine phosphorylation by T-cell protein tyrosine phosphatase.  Molecular and Cellular Biology.  Mar 1, 24 (5): 2190-2201. [PubMed]
  • Jake Kushner, Fawaz Haj, Lori Klaman, Mathew Dow, Barbara Kahn, Benjamin Neel and Morris White (2004).  Islet-sparing effects of protein tyrosine phosphatase-1b deficiency delays onset of diabetes in IRS2 knockout mice.  Diabetes.  Jan, 53 (1): 61-66.[PubMed]
  • Gustavo Sajnani-Perez, John Chilton, Radu Aricescu, Fawaz Haj, Andrew Stoker (2003).  Isoform-specific binding of the tyrosine phosphatase PTPs to a ligand in developing muscle.  Molecular and Cellular Neuroscience.  Jan, 22 (1): 37-48. [PubMed]
  • Fawaz Haj, Boyka Markova, Lori Klaman, Frank Bohmer and Benjamin Neel (2003).  Regulation of receptor tyrosine kinase signaling by protein tyrosine phosphatase-1B.  Journal of Biological Chemistry.  Jan 10, 278 (2): 739-44. [PubMed]
  • Janice Zabolotny, Kendra Bence, Alain Stricker-Krongrad, Fawaz Haj, Young-Ping Wang, Yasuhiko Minokoshi, Young-Bum Kim, Joel Elmquist, Luois Tartaglia, Barbara Kahn, Benjamin Neel (2002).  PTP1B regulates leptin signal transduction in vivo.  Developmental Cell.  Apr, 2 (4): 489-95. [PubMed]
  • Fawaz Haj, Peter Verveer, Anthony Squire, Benjamin Neel and Philippe Bastiaens (2002).  Imaging sites of receptor dephosphorylation by PTP1B on the surface of the endoplasmic reticulum.  Science.  Mar, 295 (5560): 1708-11. [PubMed]
  • Matthias Ledig, Fawaz Haj, John Bixby, Andrew Stoker and Bernhard Mueller (1999).  The receptor protein tyrosine phosphatase CRYPa promotes intraretinal axon growth.  Journal of Cell Biology.  Oct, 147 (2): 375-88. [PubMed]
  • Fawaz Haj, Iain Mckinnell and Andrew Stoker (1999).  Retinotectal ligands for the receptor tyrosine phosphatase CRYPa.  Molecular and Cellular Neuroscience.  Sep, 14 (3): 225-40. [PubMed]
  • Andrew Stoker, Bernhard Gehrig, Fawaz Haj and Boon-Huat Bay (1995).  Axonal localization of the CAM-like tyrosine phosphatase CRYPa: a signaling molecule of embryonic growth cones.  Development.  Jun, 121 (6): 1833-44. [PubMed]