Ph.D. University of California at San Diego and the Salk Institute for Biological Studies, 1996

B.Sc. University of Science and Technology of China, 1988

Our research interests focus on the following fields:

1. Deciphering the signaling pathways mediated by proteases and by Ca²⁺ using systems biology approaches. We address the problems using mRNA-displayed proteomes from human, mouse, Drosophila, and C. elegans. Current projects in the lab include: (a) to identify the family member-specific natural substrate repertoire of different caspases and granzymes; (b) to decipher the signaling pathways of several regulatory proteins identified from the selection; and (C) to identify potential drug targets that are involved in the pathogenesis of cancer and neurodegenerative diseases.

2. Developing novel protein therapeutics that can be used in tumor diagnosis and treatment. We use molecular evolution approaches to develop novel antibody mimics, on the basis of the scaffolds of several stable protein domains and non-mammalian antibodies, that bind to biomarkers on the surface of cancer cells. We conjugate these target-binding antibody mimics to small molecule drugs or nanoparticles for the targeted delivery of therapeutic agents.

3. Identifying the protein targets of drugs or drug candidates whose action mechanisms are unknown. We combine molecular proteomic and chemical biology approaches to identify the protein targets of drugs whose target-binding affinities are modest. Current project in this field is a collaborative effort with the Kohn lab to identify the targets of anti-epilepsy drug lacosamide from the proteome of mouse.

The Liu lab is at Division of Medicinal Chemistry and Natural Products at the School of Pharmacy. The lab is also affiliated to the Carolina Center for Genome Sciences and the Carolina Center of Cancer Nanotechnology Excellence. The projects in the Liu lab are funded by the National Institute of Neurological Disorders and Stroke, the American Cancer Society, the National Cancer Institute, and the National Institute of Diabetes and Digestive and Kidney Diseases.

Recent Publications:

Shen, X., Valencia, C. A., Szostak, J. W., Dong, B., and Liu, R. (2005) “Scanning the Human Proteome for Calmodulin-binding Proteins”; Proceedings of the National Academy of Sciences of US, 102, 5969-5974.

Dong, B., Valencia, C. A., and Liu, R. (2007) “Ca²⁺/CaM Directly Interacts with the PH Domain of AKT1”; Journal of Biological Chemistry, 282 (34), 25131-40.

Huang, B. and Liu, R. (2007) “Comparison of mRNA-Display Based Selections Using Synthetic Peptide and Natural Protein Libraries”, Biochemistry, 46 (35), 10102-10112.

Ju, W., Valencia, C. A., Pang, H., Ke, Y., Gao, W., Dong, B., and Liu, R. (2007) “Proteome-wide Identification of Member-specific Natural Substrate Repertoire of Caspases”; Proceedings of the National Academy of Sciences of US, 104, 14294-14299.

Kim, J. S., Valencia, C. A., Liu, R., and Lin, W. (2007) “Highly-Efficient Purification of Native Polyhistidine-Tagged Proteins by Multivalent NTA-Modified Magnetic Nanoparticles”, Bioconjugate Chemistry, 18 (2), 333-341.

Valencia, C. A., Ju, W., and Liu, R. (2007) “Matrin 3 is a Ca²⁺/Calmodulin-binding Protein Cleaved by Caspases”, Biochemical and Biophysical Research Communications, 361 (2), 281-286.

Valencia, C. A., Bailey, C., and Liu, R. (2007) “Novel Zebrafish Caspase-3 Substrates”, Biochemical and Biophysical Research Communications, 361 (2), 311-316.

Shen, X., Valencia, C. A., Gao, W., Cotten, S.W., Dong, B., Huang, B., and Liu, R. (2007) “Ca²⁺/calmodulin-binding Proteins from the C. elegans Proteome”; Cell Calcium, 43 (5), 444-456. [Epub ahead of print] PMID: 17854888.

Duan, J., Wu, J., Valencia, C. A., and Liu, R. (2007) “Fibronectin Type III Domain Based Monobody with High Avidity”, Biochemistry, 46 (44), 12656-12664.

Valencia, C. A., Cotten, S. W., and Liu, R. (2007) "Cleavage of BNIP-2 and BNIP-XL by Caspases", Biochemical and Biophysical Research Communications, 364 (3), 495-501.

Valencia, C. A., Cotten, S. W., Duan, J., and Liu, R. (2008) "Modulation of Nucleobindin-1 and Nucleobindin-2 by Caspases", FEBS Letters, 582 (2), 286-290.

Dong, B. and Liu, R. (2008) "Characterization of Endogenous and Recombinant Human Calpain-10", Biochimie, 90, 1362-1371.

Valencia, C. A., Cotten, S. W., Dong, B., and Liu, R. (2008) "mRNA-display-based Selections for Proteins with Desired Functions: A Protease-Substrate Case Study" (Review), Biotechnology Progress, 24 (3), 561-569.