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Sankari Lab

We seek to uncover the mechanisms of action of host-secreted peptides that provide important clues to decipher the fundamental biology of host-microbe interactions.

Research Summary

How do peptides modulate the metabolism of bacteria?

Research Areas

Biochemistry, Genetics and Genomics, Molecular and Cell Biology, Microbiology, Host-Microbe Interaction, Plant-Microbe Symbiosis, Metal Homeostasis

Organisms

Bacteria, Plants

The Sankari Lab works at the interface of biochemistry, cell biology, microbial physiology, and plant biology to understand the mechanism of action of host plant peptides and translate them to clinical applications. Host peptides in plants play an important role in governing the molecular interplay between microbes.

The role of host peptides in the elimination of pathogenic bacteria is well studied, yet the mechanism of how they act on symbiotic bacteria and how the bacteria tolerate these peptides is complex and is a focus of the lab. Research following the detailed mechanism of one of the host peptides from alfalfa demonstrated how peptides have evolved to fine-tune the cellular metabolism of bacteria, and has unlocked a broad field of study involving a large set of uncharacterized peptides that have specifically evolved to manipulate bacteria.

The Sankari Lab develops tools and methodologies to study the action of host peptides of interest on bacteria and utilizes them to understand their biological functions. Ongoing research aimed at improving human health and agriculture exploits their physiochemical properties to develop clinical, biotechnological, bioremediation, and sustainable agricultural applications. The lab also works on understanding the nuances of metal homeostasis during symbiosis. Trace metal nutrients, while toxic in high concentrations, are essential resources delicately shared between the host and symbiotic bacteria with host peptides maintaining this balance.

Future research will expand understanding of other components frequently present in the plant vesicles (RNAi, small molecules) that are directed from plants toward symbiotic bacteria. The lab will also explore the role of host peptides in maintaining and modulating the gut commensal ecosystem.

Assistant Investigator

Siva Sankari

Assistant Investigator

Stowers Institute for Medical Research

Why we study plants

Plants being non-motile, always come up with innovative solutions for complex problems. They have figured out a way to grow in low-nitrogen soil by establishing a one-to-one symbiotic relationship with soil bacteria. Some plants have manipulated this relationship to the extreme.

Studying the fundamental biology of this relationship gives us valuable information about how hosts evolve to manipulate beneficial bacteria in many different ways and how the bacteria evolve tolerance mechanisms.

This naturally occurring one host, one microbe association provides a simplified model to study host-microbe interaction and discoveries made in this simple model can be translated into understanding more complex host-microbiome interactions.

Why we study bacteria


Sinorhizobium meliloti and Bradyrhizobium japonicum (two soil bacteria we study) form chronic intracellular infections in leguminous plants. They can be propagated and studied as free-living bacteria in the lab and as a symbiont when living within the plant. They are harmless to humans and can be genetically modified. This system offers us the unique advantage of studying a microbe in isolation and when associated with the host with relative ease.

S. meliloti and B. japonicum belong to the bacterial subdivision of alpha-proteobacteria. Many intracellular pathogens that are difficult to study including Brucella sp. belong to this group. Discoveries made in harmless S. meliloti and B. japonicum have been translated to study other intracellular pathogens that belong to this group. The mitochondria in eukaryotes have their origins in the ancient bacteria that belong to this group. These bacteria have evolved unique cellular mechanisms and offer interesting insights into various ways of unicellular life.

Lab Philosophy

The Sankari Lab will be a welcoming and safe environment for everyone to share ideas, mentor each other, and grow together. We will work towards developing a culture of conscious listening amongst every member of the lab and receive constant feedback from every member to develop a sense of belonging to the lab.

Our lab is committed to ensuring every member’s physical and mental well-being and supporting them in maintaining their work-life balance. Our lab will be a place where every individual can feel supported, help each other in achieving their full potential as students/scientists, and as a stepping stone towards realizing their dreams.

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