# DOMAIN STRUCTURE OF HUMAN SMOOTH MUSCLE FILAMIN

> **NIH NIH R01** · WISTAR INSTITUTE · 1989 · $151,873

## Abstract

The long range goal of this proposal is to characterize the functional
roles of filamin, an important major component of smooth muscle and most
other tissues.  It is now clear that this protein is a major organizer of
three dimensional actin filament arrays and it is likely to play a critical
role in normal and diseased smooth muscle.  Our long range goal will be
approached through investigation of structural and functional properties of
both the intact molecule and domain peptides.  Functional sites on the
filamin molecule will be more precisely located and characterized in
greater detail.  A major emphasis will involve the study of the regulation
of filamin functions (self-association and actin binding) and factors that
are likely to regulate these interactions.  Possible changes in filamin
organization, quantity and isoform distribution in several pathological
states involving smooth muscle will also be investigated.

For most studies, mild proteolysis will be used to divide this large
multifunctional protein into smaller peptide units or domains.  To
facilitate the characterization of functional sites, a preliminary domain
map of the molecule will be completed using conventional and HPLC peptide
mapping.  Functional properties of filamin will be investigated using
established and novel methods for measuring protein - protein interactions
in vitro.  Pairwise protein associations and more complex multiprotein
complexes will be analyzed.  Attempts will be made to more precisely locate
binding sites on the filamin molecule using several methods including:
chemical crosslinking, site directed antibodies, and synthetic peptides.
Biochemical and protein chemical methods will be used to search for factors
that control and modulate known functional interactions.  Possible
regulatory factors that will be investigated include:  phosphorylation and
other posttranslational modifications, proteins or other factors whose
interactions with filamin have not yet been identified, calpain cleavage,
and ionic environment (especially Ca2+ levels).  Also, biochemical methods
and immunological probes developed in the above studies will be used to
characterize filamin content, isoform expression and subcellular
localization in normal and diseased smooth muscle.

## Key facts

- **NIH application ID:** 3159137
- **Project number:** 1R01AR039158-01A1
- **Recipient organization:** WISTAR INSTITUTE
- **SAM.gov UEI:** DW1XZMGNFBL4
- **Principal Investigator:** DAVID W. SPEICHER
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 1989
- **Award amount:** $151,873
- **Award type:** 1
- **Project period:** 1988-12-01 → 1993-11-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/3159137

## Citation

> US National Institutes of Health, RePORTER application 3159137, DOMAIN STRUCTURE OF HUMAN SMOOTH MUSCLE FILAMIN (1R01AR039158-01A1). Retrieved via MORVS 2026-10-24 from https://api.morvs.ai/grant/nih/3159137. Licensed CC0.

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