# REVERSIBLE FORMATION AND STRUCTURE OF ACTIN NETWORKS

> **NIH NIH R01** · BRIGHAM AND WOMEN'S HOSPITAL · 1991 · $186,802

## Abstract

The goal of the proposed work is to provide information that will help in
the understanding of how cells move and change shape.  Cell motility is
necessary for such physiologic processes as phagocytosis, platelet
response during blood coagulation, wound healing, and neurologic
development.  The proposed research will explore three aspects of this
problem, using a combination of biochemical and biophysical techniques.
The first project will define how the structure and reactivity of
proteins already thought to be needed for motility are affected by the
intracellular biochemical changes that occur as the result of stimuli
that cause cell motion.  Specifically, the effects of calcium ions and
polyphosphoinositides (PPI's) on the polymerizable protein actin and its
regulatory proteins gelsolin and profilin will be examined using optical
methods that have been developed to quantify the length and concentration
of filaments formed by actin.  Understanding the link between cell
signalling and motility is important for understanding the defects that
cause impaired or uncontrolled movement and proliferation.  Second, the
material properties of all three of the major filamentous proteins
(F-actin, microtubules, and intermediate filaments) that are thought to
endow a cell with mechanical strength will be measured.  These studies
will directly compare, for the first time, the physical properties of all
three types of filaments in order to ascertain the special features of
each type, which may suggest specialized roles for different filaments
within the cytoplasm.  These studies will employ specialized instruments
commonly used in polymer physics to measure the strength and elasticity
of various filament networks as molecular properties such as length or
stiffness of filaments, or the presence of links between filaments are
varied by different regulatory proteins.  This work may help identify
which proteins or metabolites cause particular morphologic changes
observed in living cells.  The third project will attempt to identify how
the forces causing motion in non-muscle cells are generated.  Currently
there are several different theories describing how such forces could be
generated, but experimental data to distinguish among them are lacking.
This work will involve forming simple biochemical models for cells which
contain actin or other proteins enclosed within phospholipid bilayer
vesicles.  Various reactions will be cause to occur within these vesicles
and changes in size and shape will be measured by, light or electron
microscopy, and by conventional and quasielastic light scattering.

## Key facts

- **NIH application ID:** 3158936
- **Project number:** 2R01AR038910-04A1
- **Recipient organization:** BRIGHAM AND WOMEN'S HOSPITAL
- **SAM.gov UEI:** QN6MS4VN7BD1
- **Principal Investigator:** Paul A Janmey
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 1991
- **Award amount:** $186,802
- **Award type:** 2
- **Project period:** 1991-06-01 → 1996-05-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/3158936

## Citation

> US National Institutes of Health, RePORTER application 3158936, REVERSIBLE FORMATION AND STRUCTURE OF ACTIN NETWORKS (2R01AR038910-04A1). Retrieved via MORVS 2026-10-25 from https://api.morvs.ai/grant/nih/3158936. Licensed CC0.

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