# SENSORY TRANSDUCTION IN BACTERIAL CHEMOTAXIS

> **NIH NIH R01** · HARVARD UNIVERSITY · 1988 · $221,845

## Abstract

Motile bacteria possess a stimulus-response system in which the input is
the local concentration of an attractant or repellent and the output is the
motion of the cell.  It is known that some chemicals, e.g., sugars and
amino acids, are sensed by specific receptors and that changes in receptor
occupancy lead to changes in flagellar rotational bias (the probability
that the flagella spin counterclockwise), but the way in which the
receptors are coupled to the flagella remains obscure.  We will continue
our studies of the physiology of this system by examining the rotational
behavior of tethered cells of Escherichia coli exposed to step and impulse
stimuli.  From responses of genetically engineered strains containing
modified tar (aspartate receptor) and tsr (serine receptor) proteins, we
expect to learn how information about receptor occupancy crosses the
cytoplasmic membrane and how different receptor classes interact.  From the
responses of flagellar markers on filamentous cells stimulated at different
points along their length, we will determine the physical properties of the
substance that carries information from the receptors to the flagella.  We
should be able to determine its diffusion coefficient and its size.  By
tracking and tethering cells from the same culture and comparing their
swimming and rotational behavior, we expect to learn more about
synchronization of different flagella in the same cell.  This work
complements that on genetics and biochemistry pursued in other
laboratories.  The long-range goal is an understanding at the molecular
level of basic processes involved in receptor function and sensory
transduction.

## Key facts

- **NIH application ID:** 3126666
- **Project number:** 5R01AI016478-09
- **Recipient organization:** HARVARD UNIVERSITY
- **SAM.gov UEI:** LN53LCFJFL45
- **Principal Investigator:** HOWARD C BERG
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 1988
- **Award amount:** $221,845
- **Award type:** 5
- **Project period:** 1986-12-01 → 1989-11-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/3126666

## Citation

> US National Institutes of Health, RePORTER application 3126666, SENSORY TRANSDUCTION IN BACTERIAL CHEMOTAXIS (5R01AI016478-09). Retrieved via MORVS 2026-10-25 from https://api.morvs.ai/grant/nih/3126666. Licensed CC0.

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