- The overall goals of our NIGMS-supported research have been to determine how EGF receptor (EGFR) family members and Rho GTPases trigger signaling pathways essential for normal biological processes and, when de-regulated, give rise to disease states. Our work has relied upon a combination of biochemical, cell biological, and structural approaches, as well as more recently, mouse models. These efforts led to our discovery of a novel signaling-pathway that results in the activation of a key metabolic enzyme, glutaminase C (GAC), which catalyzes the first step in glutamine metabolism and is essential for highly proliferative cells including cancer cells. We then discovered that an important outcome of these metabolic changes is the generation of microvesicles (MVs), a specific subset of non-classical secretory vesicles that fall within the larger family of extracellular vesicles (EVs). MVs, together with the other major class of EVs, exosomes, are now garnering a great deal of attention because of their roles in a wide range of normal physiological processes as well as in different diseases. They have been linked to biological activities that span the evolutionary spectrum from bacteria to viral infectivity, and to a diversity of physiological processes in higher organisms including the immune response and neuronal function, as well as being connected to diseases such as cancer and neurodegenerative disorders. Moreover, EVs have also been implicated in stem cell biology, with our laboratory recently discovering that MVs shed from embryonic stem cells play a critical role in activating trophoblasts, an essential step in embryo implantation. Still, we are at an early stage in understanding the actions of these novel modes of information transfer between cells. In particular, there is a critical need to define the biochemical and signaling mechanisms that underlie MV functions. Among the important questions surrounding this exciting field include what are the signaling mechanisms responsible for the biogenesis of MVs by cancer cells where their actions have been most heavily studied, as well as the specific cues that dictate the loading of MVs with protein and RNA cargo, and whether they are conserved across different cell types. Moreover, we need to learn much more about the nature of the signals that trigger the shedding of MVs from their parental (donor) cells, thus enabling them to engage and transfer protein and RNA cargo to their target cells. Addressing these questions will require a number of new lines of research and development, as they represent an important and rapidly emerging frontier in signal transduction. Given our laboratory's experience and expertise, we are well positioned to define the signaling mechanisms responsible for the biogenesis and function of this novel form of intercellular communication, which ultimately should yield new insights into fundamentally important biological processes, as well as the molecular basis of various diseases and pathological disorders.

Public Health Relevance

Microvesicles are shed by a number of cell types and have been implicated in a broad range of biological events and disease processes. However, thus far very little is known about the signaling cues that drive their biogenesis in different cellular contexts, how they are loaded with specific protein and RNA cargo, and how they are shed from their parent cells in order to engage their target cells to mediate a variety of physiological functions. By understanding the mechanistic basis of these processes, we expect to gain new insights into a novel form of cell-cell communication that should highlight new targets and strategies for therapeutic intervention.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Unknown (R35)
Project #
3R35GM122575-03S1
Application #
9888725
Study Section
Special Emphasis Panel (ZGM1)
Program Officer
Koduri, Sailaja
Project Start
2017-05-01
Project End
2022-04-30
Budget Start
2019-05-01
Budget End
2020-04-30
Support Year
3
Fiscal Year
2019
Total Cost
Indirect Cost
Name
Cornell University
Department
Other Basic Sciences
Type
Schools of Veterinary Medicine
DUNS #
872612445
City
Ithaca
State
NY
Country
United States
Zip Code
14850
Munir, Annum; Abdullahu, Leonora; Damha, Masad J et al. (2018) Two-step mechanism and step-arrest mutants of Runella slithyformis NAD+-dependent tRNA 2'-phosphotransferase Tpt1. RNA 24:1144-1157
Milano, Shawn K; Wang, Chenyue; Erickson, Jon W et al. (2018) Gain-of-function screen of ?-transducin identifies an essential phenylalanine residue necessary for full effector activation. J Biol Chem 293:17941-17952
Huang, Qingqiu; Stalnecker, Clint; Zhang, Chengliang et al. (2018) Characterization of the interactions of potent allosteric inhibitors with glutaminase C, a key enzyme in cancer cell glutamine metabolism. J Biol Chem 293:3535-3545
Lukey, Michael J; Katt, William P; Cerione, Richard A (2017) Targeting amino acid metabolism for cancer therapy. Drug Discov Today 22:796-804
Yoo, Sungsoo M; Latifkar, Arash; Cerione, Richard A et al. (2017) Cool-associated Tyrosine-phosphorylated Protein 1 Is Required for the Anchorage-independent Growth of Cervical Carcinoma Cells by Binding Paxillin and Promoting AKT Activation. J Biol Chem 292:3947-3957
Cluntun, Ahmad A; Lukey, Michael J; Cerione, Richard A et al. (2017) Glutamine Metabolism in Cancer: Understanding the Heterogeneity. Trends Cancer 3:169-180
Yoo, Sungsoo M; Cerione, Richard A; Antonyak, Marc A (2017) The Arf-GAP and protein scaffold Cat1/Git1 as a multifaceted regulator of cancer progression. Small GTPases :1-9
Feng, Qiyu; Zhang, Chengliang; Lum, David et al. (2017) A class of extracellular vesicles from breast cancer cells activates VEGF receptors and tumour angiogenesis. Nat Commun 8:14450
Stalnecker, Clint A; Erickson, Jon W; Cerione, Richard A (2017) Conformational changes in the activation loop of mitochondrial glutaminase C: A direct fluorescence readout that distinguishes the binding of allosteric inhibitors from activators. J Biol Chem 292:6095-6107
Desrochers, Laura M; Antonyak, Marc A; Cerione, Richard A (2016) Extracellular Vesicles: Satellites of Information Transfer in Cancer and Stem Cell Biology. Dev Cell 37:301-309

Showing the most recent 10 out of 14 publications