Professor and Director

Dept. of Medicine
Division of Endocrinology, Diabetes and Metabolism

Contact Information:

Office Address: BDB 861
Phone: 205-934-9877
Websites: Div. of Endocrinology Faculty Page
School of Medicine Faculty Profile


University of Pennsylvania, Philadelphia, PA
BA, 1980

Harvard Medical School, Boston, MA
MD, 1984

Post-Graduate Training:

Washington University, St. Louis, MO
Resident, Internal Medicine, 1984-7

National Institutes of Health, Bethesda, MD
Fellow, 1987-91

Research Description:

The focus of research in my laboratory is in understanding mechanisms of action of growth hormone (GH), an important metabolic and growth promoting hormone. In particular, I am interested in various aspects of GH receptor (GHR) structure and signal transduction. Our studies have examined the interaction of the GHR with a critical non-receptor cytoplasmic tyrosine kinase, JAK2, which is required for initiation of GHR signaling. We have explored the downstream signaling pathways (STAT, MAP kinase, and PI-3 kinase) activated by GH and their effects on GH-induced gene expression. Further, we are interested in the cellular determinants of sensitivity to GH and modulation of GHR availability and function. Current efforts include: 1) molecular studies of mechanisms of GH-induced activation of the JAK2 tyrosine kinase and the role of JAK2 in GHR stability and trafficking; 2) studies of mechanisms of generation of GH binding protein (GHBP), the shed extracellular domain of the GHR found in the circulation of humans, rabbits, and rodents that may modulate GH signaling; 3) development of anti-GHR antagonistic antibodies and their potential therapeutic potential; 4) crosstalk between the GH and epidermal growth factor (EGF) signaling pathways, particularly EGF receptor and the oncogene, ErbB-2; and 5) crosstalk between the GH and insulin-like growth factor-1 (IGF-1) signaling systems. Multiple techniques including molecular and cell biological and protein chemistry approaches are being employed to achieve these goals. Through my leadership role in translational research as Co-Director (and co-PI) of the UAB Center for Clinical and Translational Science (CCTS;, I facilitate the translation of fundamental research in diabetes to clinical application. The CCTS is UAB’s NIH-funded CTSA, an award that helps to fund this trans-institutional center with major efforts pertaining to clinical research resources, training and education, investigator services, and institutional research priorities. In my role, I assist the Director (Robert Kimberly, M.D.) in all aspects of the Center, focusing particularly on coordination of clinical services and clinical trials, the establishment and growth of a partnership network with institutions outside of UAB, and the development of novel programs to assist investigators in project design and implementation.


DRC Membership Category:

Senior Scientist