# ACTIN-BASED REGULATION OF SMOOTH MUSCLE CONTRACTION

> **NIH NIH R01** · EAST CAROLINA UNIVERSITY · 1993 · $84,335

## Abstract

The contraction of skeletal, cardiac and smooth muscles occurs by an ATP
dependent interaction of the proteins myosin and actin.  These same
proteins are also required for several critical processes, such as cell
division, in nonmuscle cells.  The force producing interaction between
actin and myosin is regulated by changes in either myosin or actin.
Whereas skeletal and cardiac muscle are regulated primarily through the
actin filament, by the proteins tropomyosin and troponin, smooth muscle
has been thought to be regulated by the level of phosphorylation of
myosin.  Evidence from several laboratories suggest that smooth muscle
contraction may also be modulated by actin binding proteins.  Two
proteins implicated in this activity are caldesmon and calponin.  Both
proteins are known to inhibit the high rate of ATP hydrolysis that occurs
in the presence of both myosin and actin.  We hope to determine the
mechanism by which these proteins function and make particular note of
differences with the tropomyosin-troponin system of skeletal and cardiac
muscle.  This will be done by determining the effect of these proteins,
individually and in combination, on the binding of various chemical
states of myosin to actin.  We will also use stopped flow kinetic
measurements to determine the effect of these proteins on key transitions
between actomyosin states.  We also hope to demonstrate the function of
these proteins in smooth muscle cells.  Differences in regulation from
skeletal and cardiac muscle may be exploited for the intervention of
hypertension, uterine disorders, digestive disorders or other disorders
involving smooth muscle contraction.

## Key facts

- **NIH application ID:** 3157107
- **Project number:** 2R01AR035216-09
- **Recipient organization:** EAST CAROLINA UNIVERSITY
- **SAM.gov UEI:** HWPEKM8VFTJ9
- **Principal Investigator:** JOSEPH M CHALOVICH
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 1993
- **Award amount:** $84,335
- **Award type:** 2
- **Project period:** 1985-04-01 → 1998-03-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/3157107

## Citation

> US National Institutes of Health, RePORTER application 3157107, ACTIN-BASED REGULATION OF SMOOTH MUSCLE CONTRACTION (2R01AR035216-09). Retrieved via MORVS 2026-10-24 from https://api.morvs.ai/grant/nih/3157107. Licensed CC0.

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