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United States Department of Agriculture

Agricultural Research Service

CHRIS HAWKES

Research Chemist

 

 

 

Ph.D., Biochemistry Graduate Group

 

University of California, Davis

 

Office:  430 West Health Sciences Dr.

             University of California

             Davis, CA 95616

             

Phone:  (530) 752-4765

 

Fax:      (530) 752-4765

   

 

 

Hawkes Lab Home

 

 

Biography

 

A native Californian, Chris Hawkes earned his BS in Chemistry at the University of California, Berkeley. After a break working in the radiopharmaceutical industry, Chris earned his Ph.D. degree in Biochemistry from the University of California, Davis. Dr. Hawkes joined the staff of the USDA Western Human Nutrition Research Center at the Presidio of San Francisco in 1984 and joined the UC Davis Department of Nutrition as an adjunct professor when the WHNRC moved to Davis in 1999.

Research Program

 

Dr. Hawkes’ research concerns selenium and chronic disease prevention, particularly the role of selenoproteins in redox regulation, cell cycle control, and inflammatory signaling pathways. His current research is focused on the role of the small selenoprotein SEPW1 in propagation of epidermal growth factor signaling. A combination of biochemical, molecular biological, and proteomic approaches are being applied to identify the enzymatic activity and molecular function of SEPW1.

 

Research Accomplishments

 

·         Dr. Hawkes discovered selenocysteine transfer RNA and showed that selenocysteine is incorporated into selenoproteins directly from tRNA during protein synthesis. Selenocysteine is now recognized as the 21st amino acid in the genetic code.

 

·         Dr. Hawkes showed that at least 85% of the selenium in rats is present as selenocysteine in a group of 20-25 selenoproteins. This led to the recognition that selenoproteins are responsible for the biological effects of selenium.

 

·         Dr. Hawkes demonstrated that monkey fetuses are protected from toxic levels of selenium by the placenta.  This work demonstrated that pregnant women are not at risk from eating foods from high selenium areas, which are common in major agricultural production areas of the Western United States.

 

·         Dr. Hawkes discovered that selenoprotein W (SEPW1) is required for epidermal growth factor signaling and that lack of SEPW1 causes a p38-, p53-, and p21-dependent cell cycle arrest. Because SEPW1 is the only selenoprotein increased by selenium supplementation, it may be responsible for at least some of the effects of selenium supplements. 

Selected Articles & Patent Applications

1.       Hawkes W.C., Alkan Z. Delayed Cell Cycle Progression in Selenoprotein W Depleted Cells Is Regulated By a Mitogen-Activated Protein Kinase Kinase 4 (MKK4)-p38/c-Jun NH2-Terminal Kinase (JNK)-p53 Pathway. J Biol Chem. 2012;287:27371-9.

 

2.       Hawkes W.C., Printsev I, Alkan Z. Selenoprotein W Depletion Induces a p53- and p21-Dependent Delay in Cell Cycle Progression in RWPE-1 Prostate Epithelial Cells. J Cell Biochem 2012, 113(1):61-69.

 

3.       Hawkes, W.C., Alkan, Z. 2011. Delayed cell cycle progression from SEPW1 depletion is p53- and p21-dependent in MCF-7 breast cancer cells. Biochemical and biophysical research communications. 413:36-40.

 

4.       Hawkes, W.C., Alkan, Z. 2010. Regulation of redox signaling by selenoproteins. Biological Trace Element Research. 134(3): 235-251, 2010.

 

5.       Hawkes W.C., Wang TTY, Alkan Z, Richter BD, Dawson K: Selenoprotein W Modulates Control of Cell Cycle Entry. Biol Trace Elem Res 2009, 131(3):229-244.

 

6.       Hawkes W.C., Laslett LJ. Selenium supplementation does not improve vascular responsiveness in healthy North American men. American journal of physiology Heart and circulatory physiology. 2009;296:H256-H62.

 

7.       Hawkes W.C., Hwang A, Alkan Z. The Effect of Selenium Supplementation on DTH Skin Responses in Healthy North American Men. J Trace Elem Med Biol. 2009;23:272-80.

 

8.       Hawkes W.C., Alkan Z., Wong K. Selenium Supplementation Does Not Affect Testicular Selenium Status or Semen Quality in North American Men. J Androl. 2009;30:525-33.

 

9.       Hawkes W.C., Richter B.D., Alkan Z., Souza E.C., Derricote M., Bonnel E.L.: Response of selenium status indicators to supplementation of healthy North American men with high-selenium yeast. Biol Trace Elem Res 2008, 122(2):107-121.

 

10.   Hawkes, W.C., C.C. Willhite, S.T. Omaye, D.N. Cox, W.N. Choy, and A.F. Tarantal. 1994. Selenium kinetics, placental transfer, and neonatal exposure in cynomolgus macaques (Macaca fascicularis). Teratology. 50:148-159. 

 

11.   Willhite, C.C., W.C. Hawkes, S.T. Omaye, W.N. Choy, D.N. Cox, and M.J. Cukierski. 1992. Absorption distribution and elimination of selenium as l selenomethionine in non-human primates. Food Chem Toxicol. 30:903-913. 

 

12.   Hawkes, W.C., C.C. Willhite, K.A. Craig, S.T. Omaye, D.N. Cox, W.N. Choy, and H.A. G. 1992. Effects of excess selenomethionine on selenium status indicators in pregnant long-tailed macaques macaca-fascicularis. Biol Trace Elem Res. 35:281-297. 

 

13.   Hawkes, W.C., E.C. Wilhelmsen, and A.L. Tappel. 1985. Abundance and tissue distribution of selenocysteine-containing proteins in the rat. J Inorg Biochem. 23:77-92.

 

14.   Hawkes, W.C., E.C. Wilhelmsen, and A.L. Tappel. 1985. Subcellular distribution of selenium-containing proteins in the rat. J Inorg Biochem. 25:1-17. 

 

15.   Hawkes, W.C., and A.L. Tappel. 1983. In vitro synthesis of glutathione peroxidase from selenite. Translational incorporation of selenocysteine. Biochim Biophys Acta. 739:225-34.

 

16.   Hawkes, W.C., D.E. Lyons, and A.L. Tappel. 1982. Identification of a selenocysteine-specific aminoacyl transfer RNA from rat liver. Biochim Biophys Acta. 699:183-91. 

 


Last Modified: 6/10/2013
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