Biography

     Chris Hawkes grew up along the California coast south of San Francisco. After completing his lower division work at the local community college, Chris attended the University of California at Berkeley, where he obtained a BS in Chemistry. After graduation, Chris worked as a radiopharmaceutical production supervisor, manufacturing radioactive drugs for cancer imaging and diagnosis. Dr. Hawkes obtained his Ph.D. degree in Biochemistry from the University of California at Davis in 1980. After a postdoctoral appointment with Dr. Al Tappel at Davis, he joined the staff of the USDA Western Human Nutrition Research Center at the Presidio of San Francisco in 1984. Dr. Hawkes joined the UC Davis Department of Nutrition as an adjunct professor when the WHNRC moved to Davis in 1999.

Research Interests

     Dr. Hawkes conducts research on nutritional prevention of cancer, mechanisms of cancer initiation, and the role of selenoproteins in chronic disease prevention.

Research Objectives

·          Determine the mechanisms of chemoprevention with dietary selenium

·          Discover the molecular function(s) of Selenoprotein W.

·          Determine the molecular functions of selenium during mitosis.

Research Accomplishments

·         Dr. Hawkes was the first to discover selenocysteine transfer-RNA, and was the first to show that selenium is incorporated into selenoproteins as the amino acid selenocysteine, transferred directly from the transfer-RNA during protein synthesis.  Dr. Hawkes' hypothesis that selenocysteine incorporation into proteins is directed by readthrough of the UGA termination codon has been confirmed in numerous laboratories.  His discovery of this novel protein synthesis pathway opened up the field of selenoprotein research and has led to renewed interest in the mechanisms of ribosomal codon recognition.

·          By inventorying all the selenium in the bodies of rats fed only inorganic selenium salts, Dr. Hawkes was able to demonstrate that all of the selenium was present as selenocysteine incorporated into 20-25 distinct proteins, most of which were unknown at the time.  This work established that all of the biological functions of selenium are carried out by selenocysteine-containing proteins and illustrated the biological need for a special protein synthesis pathway and transfer-RNA for selenocysteine. Since the existence and significance of selenocysteine-containing proteins were demonstrated by Dr. Hawkes, many new selenoenzymes and selenoprotein genes have been discovered.

·         In his studies of selenium toxicity in pregnant monkeys, Dr. Hawkes showed that, unlike birds, primate fetuses are well-protected from selenium and are only at risk if the mother herself is poisoned by too much selenium.  This work demonstrated that pregnant women needn't be concerned about eating foods from high selenium areas, which are common in major agricultural production areas of the Western United States.

·         Since moving to Davis, Dr. Hawkes’ research group has identified a selenoprotein in breast and prostate epithelial cells that is the putative molecular target of dietary selenium for cancer prevention.