Xiaodong Cheng, Ph.D.

Associate Professor

Affiliations: Department of Pharmacology & Toxicology, Sealy Center for Cancer Cell Biology, Sealy Center for Structural Biology, NIEHS

Phone: (409) 772-1561
Fax: (409) 772-9642
Email: xcheng@utmb.edu

Education

• B.S. - 1985 Peking University, Beijing, China
• M.S. -1988 Shanghai Institute of Biochemistry, Chinese Academy of Science
• Ph.D. -1994 The University of Texas Medical Branch at Galveston
• Postdoctoral Fellow -1999 University of California-San Diego

research interests

The major research focus in our laboratory is function and regulation of protein kinases and small GTPases and their roles in cancers. Currently, there are three independent but closely related projects in the lab. The first two are related intracellular signaling mediated by cAMP. cAMP-dependent protein kinase (PKA) isoforms play different roles in regulating various cellular processes, such as cell growth and differentiation. The linkage between certain PKA isoforms and cancer has also been firmly established. However, the underlying biochemical and structural principles for isoform-specific PKA functions are not clearly understood. To bridge this gap in our understanding, we are investigating the structure and function of different PKA isoforms using biochemical, molecular and cellular approaches. Particularly, we will apply chemical-genetic and functional proteomic approaches to determine the cellularsubstrates of different PKA isoforms. Recently, a family of novel intracellular cAMP receptors, Exchange proteins directly activated by cAMP (Epac), has been discovered. The finding of a second intracellular cAMP receptor in addition to PKA suggests that some, or even the majority of cAMP actions described in the vast cAMP literature, do not act through the activation of PKA alone, as previously believed. Therefore, dissecting the functional roles of Epac in the overall cAMP-mediated intracellular signaling is another major emphasis of the lab. Finally, we are also conducting study of the molecular mechanism of ovarian cell transformation and tumorgenesis using a genetically defined ovarian cancer model and functional proteomics approaches.

Biographical Information

Xiaodong Cheng received his Ph. D. degree in Biochemistry from The University of Texas Medical Branch at Galveston in 1994. In 1995, he was awarded an American Cancer Society postdoctoral fellowship for studies with Dr. Susan S. Taylor at the University of California, San Diego. His postdoctoral research was focused on dissecting the molecular mechanism of cAMP-dependent protein kinase activation and regulation using a combination of biochemical, biophysical, and structural approaches.

Selected Publications

Mei F, Qiao J, Tsygankova OM, Meikoth JL, Quilliam LA, Cheng X. Differential Signaling of cAMP: Opposing effect of Epac and PKA on PKB Phosphorylation and Activation. J. Biol. Chem. 277:11497-11504, 2002.

Qiao J, Mei F, Popov VL, Vergare LA, Cheng X. Cell Cycle Dependent Subcellular Localization of Exchange Factor Directly Activated by cAMP. J. Biol. Chem. 277:26581-26586, 2002.

Yu S, Mei F, Lee JC, Cheng X. Probing cAMP-dependent protein kinase holoenzyme complexes by FT-IR and chemical protein footprinting. Biochemistry 43:1908-1920, 2004.

Young TW, Mei F, Yang G, Thomspon-Lanza JA, Liu J, Cheng X. Activation of anti-oxidant pathways in Ras-mediated transformation of human ovarian epithelia cell revealed by functional proteomics and mass spectrometry. Cancer Research 64:4577-4584, 2004.

Dipilato L, Cheng X, Zhang J. Fluorescent indicators of cAMP and Epac activation reveal differential dynamics of cAMP signaling within discrete subcellular compartments. Proc. Acad. Natl. Sci. USA. 101:16513-16518, 2004.

Cheng, X. Understand signal transduction through functional proteomics. Expert Review in Proteomic 2:103-116, 2005.

Zhang L, Cui R, Cheng X, Du J. Anti-apoptotic effect of serum and glucocorticoid-induced protein kinase is mediated by a novel mechanism activating IkB Kinase. Cancer Research 65:457-464, 2005.