# PLASMA MEMBRANE CHANGES IN FERTILIZATION

> **NIH NIH R01** · STATE UNIVERSITY NEW YORK STONY BROOK · 1994 · $139,187

## Abstract

Despite great advances in our understanding of the structure and function
of receptors in somatic cells, relatively little is known about receptors
involved in the cell-cell interactions that occur at fertilization.  Work
in a prior grant period on the sea urchin egg receptor that binds sperm
established that the receptor was protease-sensitive and that its release
resulted in loss of ability of sperm to bind to and fertilize these eggs.
Furthermore, it was established that proteolytically-released fragments
inhibited fertilization in a species-specific manner.  Subsequently, it was
shown that the intact receptor was a complex proteoglycan-like molecule.
Evidence was also obtained that the carbohydrate chains of the receptor
serve as the adhesive element of the molecule, whereas the polypeptide
chain defines the species specificity of the binding process.  Given the
extreme insolubility and apparent high molecular weight of the intact
receptor, procedures were developed to isolate fragments of it that
retained species specificity.  One of these fragments, presumed to be a
portion of the extracellular domain of the receptor, was purified to
homogeneity by gel filtration and anion exchange chromatography and shown
to be a 70-kDa glycosylated peptide.  This receptor fragment binds to sperm
species specifically.

The current proposal has five objectives.  First, the primary structure of
the intact receptor, and the sites of attachment and the structure(s) of
its oligosaccharide chains will be defined.  Second, having established the
basic structural features of the receptor molecule, a variety of methods
will be used to partially degrade it so as to define the structural basis
of its species specificity, especially with respect to the role of the
polypeptide backbone and the oligosaccharide chains.  Third, potential
additional ligands for the receptor will be identified.  Although it is
clear that bindin from the sperm acrosome is one ligand involved in
interaction with the egg receptor, it is not known if other sperm
components are involved.  Fourth, the apparent activation of eggs by
antibody to the 70-kDa receptor fragment will be compared with a variety of
"early activation events" induced by sperm.  By microinjection of
inhibitors or activators of known signal transduction pathway components it
should be possible to determine if these components are involved in the
sperm receptor system.  If primary structure analysis indicates that the
receptor is a transmembrane protein, it will be reconstituted into the
plasma membrane of frog oocytes or starfish oocytes by microinjection of
its mRNA.  Alternatively, the intact receptor will be purified, introduced
into phospholipid liposomes and then fused with the plasmic membrane of
starfish oocytes.  Fifth, the structure of the S. purpuralus receptor will
be compared with that of other sea urchin species.  Initially, this will be
accomplished at the level of the gene, which will provide information about
...

## Key facts

- **NIH application ID:** 2197685
- **Project number:** 5R01HD018590-13
- **Recipient organization:** STATE UNIVERSITY NEW YORK STONY BROOK
- **SAM.gov UEI:** M746VC6XMNH9
- **Principal Investigator:** WILLIAM J LENNARZ
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 1994
- **Award amount:** $139,187
- **Award type:** 5
- **Project period:** 1989-08-01 → 1997-05-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/2197685

## Citation

> US National Institutes of Health, RePORTER application 2197685, PLASMA MEMBRANE CHANGES IN FERTILIZATION (5R01HD018590-13). Retrieved via MORVS 2026-10-25 from https://api.morvs.ai/grant/nih/2197685. Licensed CC0.

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