# ACROSOMAL ENZYME BIOSYNTHESIS BY SPERMATIDS

> **NIH NIH R01** · UNIVERSITY OF PENNSYLVANIA · 1994 · $183,518

## Abstract

The broad, long-term objective of this research proposal is to
understand the processes involved in the biogenesis and maturation of
the mammalian sperm acrosome, an organelle essential for fertilization.
The first specific aim is to determine when two acrosomal proteins are
first synthesized and correlate their synthesis with that of the
messenger RNA coding for their polypeptides.  This laboratory has
previously demonstrated that the synthesis one of the acrosomal
components, acrogranin, begins during meiosis and continues into earlier
spermogenesis.  The second specific aim is examine the function of
acrogranin by testing the hypothesis that it is similar to proteins
found in other secretory granules and may be involved in the packaging
of other components into the acrosome.  The third specific aim is to
examine the effects of epididymis-associated changes of acrosomal
components on their function.  First, the modification of the
oligosaccharide side-chains of the protease zymogen proacrosin will be
examined to determine if these changes affect the activated enzyme's
activity.  In addition, the stability of the acrosomal matrix of sperm
from different regions of the epididymis will be examined since changes
in the properties of this matrix may affect the ability of sperm to
undergo a complete acrosome reaction.  The final specific aim is to
examine the targeting of proacrosin and acrogranin to secretory granules
of cells of the pituitary line AtT-20 that have been transfected with
cDNAs coding for proacrosin and acrogranin.  These experiments will
utilize the methods of cell biology, biochemistry, and molecular biology
to look at the biogenesis of the acrosome.  The proteins will be
localized to specific cells organelles of cells in sections of testes by
immunocytochemistry by light and electron microscopy.  Functional assays
will look at the enzymatic activity of proacrosin/acrosin and the
aggregation characteristics of acrogranin.  During the course of the
project, cDNAs coding for both proacrosin and acrogranin will be
isolated and characterized.  These probes will allow us to look at the
expression of proacrosin and acrogranin mRNA during spermatogenesis and
to determine the deduced amino acid sequences for the proteins.
Recombinant constructs will be prepared so that these germ cell proteins
can be expressed in somatic cells.  Creation of stably transfected cell
lines expressing these proteins will allow the more facile examination
of the biosynthetic transport of these proteins.  The results from these
experiments will help explain how acrosomal proteins are transported
from the cell cytoplasm to the acrosome.  Knowledge of this process may
provide new avenues for examining cases of male idiopathic infertility
and may open new targets for contraceptive development.

## Key facts

- **NIH application ID:** 2198696
- **Project number:** 5R01HD022899-07
- **Recipient organization:** UNIVERSITY OF PENNSYLVANIA
- **SAM.gov UEI:** GM1XX56LEP58
- **Principal Investigator:** George L. Gerton
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 1994
- **Award amount:** $183,518
- **Award type:** 5
- **Project period:** 1988-02-01 → 1996-01-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/2198696

## Citation

> US National Institutes of Health, RePORTER application 2198696, ACROSOMAL ENZYME BIOSYNTHESIS BY SPERMATIDS (5R01HD022899-07). Retrieved via MORVS 2026-10-25 from https://api.morvs.ai/grant/nih/2198696. Licensed CC0.

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