# PERMEABILITY OF THE EPIDEMIC TYPHUS RICKETTSIA

> **NIH NIH R01** · UNIVERSITY OF SOUTH ALABAMA · 1989 · $239,406

## Abstract

The genus Rickettsia, including Rickettsia prowazekii, the etiological
agent of epidemic typhus, is unique, even amongst the intracellular
bacterial parasites.  These organisms grow directly in the cytoplasm,
rather than in a vacuole in the cytoplasm of their eukaryotic host cells.
We remain intensely interested in the biochemical and physiological
mechanisms by which this organism copes with the problems and exploits the
opportunities of this unique environmental niche and seek to define the
mechanisms by which the rickettsiae enter the host cell cytoplasm.  During
the next five years we hope to answer key questions concerning 1) the
transport systems for those nutrients that the rickettsia encounters in the
cytoplasm, the metabolic capabilities of R. prowazekii for these substrates
and the regulation of these processes; 2) the penetration mechanism used by
rickettsiae to infect eukaryotic cells with emphasis on both the receptor
interactions and the phospholipase A activity.

The specific aims encompassed in these general areas are:

I. Transport systems and metabolism:  a) Development of the "rickettsiae
with protein synthesis" as a system for transport studies of amino acids;
b) Utilization of the corresponding "rickettsiae with m-RNA synthesis" to
define the pathway for net ribonucleotide transport; c) Characterization of
the ATP/ADP transport system in membrane vesicles using the cloned and
expressed gene in E. coli; d) Investigation of growth and metabolism of
rickettsiae growing in transport and respiratory-deficient somatic cell
mutants; e) Characterization of the transport and metabolism of nucleotide
sugars as a possible strategy for carbohydrate metabolism of nucleotide
glycolytic enzymes; f) Investigation of proton translocation and its
relationship to proton motive force in rickettsiae.

II. Penetration-Receptors and Phospholipase A:  a) Investigation of the
role of phospholipase A2 activity in lysis of and entry into host cells; b)
Characterization of receptors of the host-cell involved in rickettsia-host
recognition using the Fluorescence Activated Cell Sorter.

## Key facts

- **NIH application ID:** 3125992
- **Project number:** 5R01AI015035-12
- **Recipient organization:** UNIVERSITY OF SOUTH ALABAMA
- **SAM.gov UEI:** QB12VPNQQFE8
- **Principal Investigator:** HERBERT H WINKLER
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 1989
- **Award amount:** $239,406
- **Award type:** 5
- **Project period:** 1979-01-01 → 1989-12-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/3125992

## Citation

> US National Institutes of Health, RePORTER application 3125992, PERMEABILITY OF THE EPIDEMIC TYPHUS RICKETTSIA (5R01AI015035-12). Retrieved via MORVS 2026-10-25 from https://api.morvs.ai/grant/nih/3125992. Licensed CC0.

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