# GENETICS AND PATHOGENICITY OF ESCHERICHIA COLI HEMOLYSIN

> **NIH NIH R01** · UNIVERSITY OF WISCONSIN-MADISON · 1988 · $157,063

## Abstract

At present the properties enabling Escherichia coli to act as one of the
major opportunistic pathogens are not well understood.  The E. coli
cytolysin/hemolysin (hly) plays a contributory role in the virulence of
extraintestinal disease, however, the nature of the interaction of the hly
with host cells on a molecular levsel is unknown.  The Hly polypeptide
subunit is 110,000 daltons in molecular mass and its predicted amino acid
sequence reveals domain-like elements based on hydropathy and isoelectric
point characteristics.  An objective of this project will be to delineate
Hly-host cell interaction by use of genetically engineered forms of the hly
protein, synthetic peptides, chemical cleavage fragments of the hly
protein, and both specific polyclonal and monoclonal antibodies.  We will
develop the domain-specific reagents for use in in vitro and in vivo assays
of the activities associated with the hemolysin.  This type of analysis has
been productively utilized in studies of diphtheria toxin and bacterial
fimbriae and will enable an understanding of an important cytolysin.  The
second main objective of this project is the continued study of the
function and regulation of transcription and translation of the four
cistrons responsible for the E. coli hly.  We will assay the altered
function and cellular location of in vitro constructed mutations of each of
the four cistrons.  These will be made by either insertion of synthetic
oligonucleotides or site-specific oligonucleotide-directed mutagenesis.  We
will quantitate and map the mRNAs by S-1 nuclease protection, Northern
blotting and primer extension techniques.  These genetic and physical
studies will lead to an understanding of the factors affecting the
expression of this virulence factor.  Overall, the long term goal of this
research program is to identify and characterize the genetic and
physiological nature of bacterial factors influencing E. coli
extraintestinal infections.  This type of information is of great value in
the development of selective strategies for the prevention and treatment of
serious bacterial diseases.

## Key facts

- **NIH application ID:** 3129909
- **Project number:** 5R01AI020323-06
- **Recipient organization:** UNIVERSITY OF WISCONSIN-MADISON
- **SAM.gov UEI:** LCLSJAGTNZQ7
- **Principal Investigator:** Rodney A. Welch
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 1988
- **Award amount:** $157,063
- **Award type:** 5
- **Project period:** 1983-08-01 → 1991-07-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/3129909

## Citation

> US National Institutes of Health, RePORTER application 3129909, GENETICS AND PATHOGENICITY OF ESCHERICHIA COLI HEMOLYSIN (5R01AI020323-06). Retrieved via MORVS 2026-10-25 from https://api.morvs.ai/grant/nih/3129909. Licensed CC0.

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