This project addresses a key issue for both biology and medicine: the discovery of small molecules that can serve as the basis for regulating biological processes and/or developing into therapeutic agents. Bacteria that live in close association with other organisms ? symbiotic bacteria ? produce small molecules to regulate the relations with their hosts and other community members, and researchers are just now beginning to appreciate the pervasiveness of these interactions and the vast array of biologically active small molecules needed to maintain them. This proposal describes three different approaches to access these small molecules and their biological functions. Two focus on specific symbioses, and the third focuses on a general strategy to screen for in vivo virulence factors. 1.
The first aim focuses on a previously unrecognized ecological niche, the bacterial symbionts of mushrooms. The motivation for this aim originated in a desire to understand the evolutionary origins of the multilateral symbioses we see today ? the original binary symbioses. Whether this evolutionary scenario is correct or not, the idea of focusing on these bacteria led to some very interesting preliminary results: the tryptorubin system of peptides with an oxidative polycyclization biosynthesis that creates a rigid, strained final product. 2.
The second aim focuses on the bacterial symbionts of plants ? the unicellular algae that photosynthesize roughly half of the world's oxygen and fix an equivalent amount of carbon. They also take part in many other global element cycles. These algae require the assistance of their bacterial symbionts to fulfill these functions. The algae and their bacterial symbionts are redistributing due to climate change in ways that we don't fully understand. Some of these algal-bacterial systems involve the production of molecules with impacts or potential impacts on human health. As examples, one makes an amnesic neurotoxin called domoic acid, and another makes a factor that induces a polyploidy phenotype ? a likely cytokinesis inhibitor that could be useful for proliferative diseases. 3. Many of the biologically active molecules that take part in complex symbioses continue to be invisible to our current discovery methods. For example, an active molecule might be made from an unusual metabolite provided by the host of another member of the community, and the `producing' bacteria might be providing a single enzyme. These molecules and processes will be invisible to standard metabolomic or genomic analyses. We have developed an in vivo screen with relatively high throughput that can help identify such processes, and the third specific aim deals with some early proof of concept applications of the screen.

Public Health Relevance

(Relevance) Addressing unmet medical needs requires the discovery of molecules that improve on current treatments or create new treatments. Many of our most effective drugs for infectious diseases, cancer, and immune disorders are derived from molecules made by environmental bacteria, and this project describes ways to discover previously unknown molecules made by previously unknown bacteria that live in close association with other living things ? insects, humans, and plants.

Agency
National Institute of Health (NIH)
Institute
National Center for Complementary & Alternative Medicine (NCCAM)
Type
Research Project (R01)
Project #
9R01AT009874-09
Application #
9380400
Study Section
Synthetic and Biological Chemistry B Study Section (SBCB)
Program Officer
Hopp, Craig
Project Start
2008-09-09
Project End
2020-07-31
Budget Start
2017-08-01
Budget End
2018-07-31
Support Year
9
Fiscal Year
2017
Total Cost
Indirect Cost
Name
Harvard Medical School
Department
Biochemistry
Type
Schools of Medicine
DUNS #
047006379
City
Boston
State
MA
Country
United States
Zip Code
02115
Van Arnam, Ethan B; Currie, Cameron R; Clardy, Jon (2018) Defense contracts: molecular protection in insect-microbe symbioses. Chem Soc Rev 47:1638-1651
Böttcher, Thomas; Szamosvári, Dávid; Clardy, Jon (2018) A Repeating Sulfated Galactan Motif Resuscitates Dormant Micrococcus luteus Bacteria. Appl Environ Microbiol 84:
Pishchany, Gleb; Mevers, Emily; Ndousse-Fetter, Sula et al. (2018) Amycomicin is a potent and specific antibiotic discovered with a targeted interaction screen. Proc Natl Acad Sci U S A 115:10124-10129
Puri, Aaron W; Mevers, Emily; Ramadhar, Timothy R et al. (2018) Tundrenone: An Atypical Secondary Metabolite from Bacteria with Highly Restricted Primary Metabolism. J Am Chem Soc 140:2002-2006
Brancucci, Nicolas M B; Gerdt, Joseph P; Wang, ChengQi et al. (2017) Lysophosphatidylcholine Regulates Sexual Stage Differentiation in the Human Malaria Parasite Plasmodium falciparum. Cell 171:1532-1544.e15
Wyche, Thomas P; Ruzzini, Antonio C; Schwab, Laura et al. (2017) Tryptorubin A: A Polycyclic Peptide from a Fungus-Derived Streptomycete. J Am Chem Soc 139:12899-12902
Liu, Yizhou; Saurí, Josep; Mevers, Emily et al. (2017) Unequivocal determination of complex molecular structures using anisotropic NMR measurements. Science 356:
Fenn, Kathrin; Strandwitz, Philip; Stewart, Eric J et al. (2017) Quinones are growth factors for the human gut microbiota. Microbiome 5:161
Guo, Chun-Jun; Chang, Fang-Yuan; Wyche, Thomas P et al. (2017) Discovery of Reactive Microbiota-Derived Metabolites that Inhibit Host Proteases. Cell 168:517-526.e18
Woznica, Arielle; Gerdt, Joseph P; Hulett, Ryan E et al. (2017) Mating in the Closest Living Relatives of Animals Is Induced by a Bacterial Chondroitinase. Cell 170:1175-1183.e11

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