The significance of understanding biomarkers to take full advantage of them in disease diagnosis and treatment as well as in biomedical research is well recognized by the science community. CD38, originally identified as a differentiation marker for hematopoietic cells, is present in many other types of cells, and its deregulation is found to contribute to several different human diseases, including leukemia, social behavior defects, diabetes, and osteoporosis. Understanding the roles CD38 plays in various normal and pathological conditions has the potential to offer new ways to treat these diseases. So far, some knowledge about CD38 has been acquired, though limited, thanks to the efforts from researchers in the field. CD38 acts both as an enzyme and a receptor. The enzymatic activity can convert nicotinamide adenine dinucleotide (NAD) to adenosine diphosphate ribose (ADPR) and cyclic ADPR (cADPR), and NAD phosphate (NADP) to nicotinic acid adenine dinucleotide phosphate (NAADP). Both cADPR and NAADP are potent Ca2+ messengers that can trigger Ca2+ release from internal stores. As a receptor, when activated by certain ligands, CD38 can trigger the phosphorylation of intracellular proteins, including c-Cbl and mitogen-activated protein kinases (MAPK). However, the exact roles CD38 plays in most normal and pathological conditions are poorly understood at present, despite the accumulation of the knowledge mentioned above. Several unanswered questions prevent a clear and complete understanding of CD38 function. For example, how CD38 gains access to its NAD or NADP substrate, whether CD38 is present in intracellular organelles, and how the receptor function affects the enzymatic function. In this proposal, we will develop and use chemical tools, particularly NAD analogs that can covalently label CD38 in live cells, to address these important questions concerning CD38 biology. These CD38 probes have unique features, such as cell permeability, compatibility with ligand binding to CD38, and the ability to inhibit CD38 enzymatic activity. These small molecule probes can be used to track CD38 trafficking in real time in live cells, determine the intracellular distribution of CD38, and isolate and identify unknown CD38 ligands. These experiments cannot be easily achieved using other methods. Our studies will lead to a more detailed mechanistic picture of CD38 biochemistry, which will help to understand the function of CD38 in various normal and pathological conditions and potentially lead to new ways to treat diseases involving CD38, such as leukemia, diabetes, autism, and osteoporosis. In addition, the NAD metabolizing capability of CD38 can have a significant impact on other NAD-dependent enzymes, particularly the NAD-dependent deacetylases (sirtuins) and poly(ADP-ribose) polymerases (PARPs). Understanding how CD38 works should shed lights on the potential interactions between CD38 and other NAD-dependent enzymes.

Public Health Relevance

CD38 is important for immune cell differentiation and function, insulin secretion, and neuropeptide release. It has been found to be involved in several human diseases, such as leukemia and diabetes. Our proposed study will help to understand the roles of CD38 plays in normal and pathological conditions, and potentially lead to new ways to treat human diseases involving CD38.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
5R01GM086703-05
Application #
8389598
Study Section
Synthetic and Biological Chemistry A Study Section (SBCA)
Program Officer
Fabian, Miles
Project Start
2008-12-01
Project End
2013-11-30
Budget Start
2012-12-01
Budget End
2013-11-30
Support Year
5
Fiscal Year
2013
Total Cost
$282,564
Indirect Cost
$98,133
Name
Cornell University
Department
Chemistry
Type
Schools of Arts and Sciences
DUNS #
872612445
City
Ithaca
State
NY
Country
United States
Zip Code
14850
Jiang, Hong; Zhang, Xiaoyu; Chen, Xiao et al. (2018) Protein Lipidation: Occurrence, Mechanisms, Biological Functions, and Enabling Technologies. Chem Rev 118:919-988
Tong, Zhen; Wang, Miao; Wang, Yi et al. (2017) SIRT7 Is an RNA-Activated Protein Lysine Deacylase. ACS Chem Biol 12:300-310
Tong, Zhen; Wang, Yi; Zhang, Xiaoyu et al. (2016) SIRT7 Is Activated by DNA and Deacetylates Histone H3 in the Chromatin Context. ACS Chem Biol 11:742-7
Gibson, Bryan A; Zhang, Yajie; Jiang, Hong et al. (2016) Chemical genetic discovery of PARP targets reveals a role for PARP-1 in transcription elongation. Science 353:45-50
Jiang, Hong; Zhang, Xiaoyu; Lin, Hening (2016) Lysine fatty acylation promotes lysosomal targeting of TNF-?. Sci Rep 6:24371
Chiang, Ying-Ling; Lin, Hening (2016) An improved fluorogenic assay for SIRT1, SIRT2, and SIRT3. Org Biomol Chem 14:2186-90
Jing, Hui; Lin, Hening (2016) Lessons learned from a SIRT2-selective inhibitor. Oncotarget 7:22971-2
Jing, Hui; Lin, Hening (2015) Sirtuins in epigenetic regulation. Chem Rev 115:2350-75
Shrimp, Jonathan H; Hu, Jing; Dong, Min et al. (2014) Revealing CD38 cellular localization using a cell permeable, mechanism-based fluorescent small-molecule probe. J Am Chem Soc 136:5656-63
Jiang, Hong; Khan, Saba; Wang, Yi et al. (2013) SIRT6 regulates TNF-? secretion through hydrolysis of long-chain fatty acyl lysine. Nature 496:110-3

Showing the most recent 10 out of 19 publications