# DESMOSOME:  STRUCTURE AND FUNCTION

> **NIH NIH R01** · UNIV OF NORTH CAROLINA CHAPEL HILL · 1991 · $173,611

## Abstract

The purpose of the planned research is to investigate assembly of
desmosomes.  The major desmosome proteins, desmoplakin I and desmoplakin
II, have been purified from pig tongue epithelium after extraction in
buffers containing 4 M urea.  The investigators will use the purified
proteins labelled with 125I-labelled Bolton-Hunter reagent in binding
experiments with purified desmosomes depleted of desmoplakins to try to
determine physiologically significant binding proteins for desmoplakins.
Desmosome proteins transferred to nitrocellulose will be used to detect the
identity of specific proteins to which desmosome bind.  The ability of
purified desmoplakins to bind to desmosomes and to participate in desmosome
assembly will also be examined in cultured cells using fluorophore-
derivatized desmoplakins injected into living cells.  The authors have
determined the structure of the desmoplakin I dimer, but it is not clear
how the two monomers associate.  Monomers will therefore be derivatized
under dissociating conditions in order to produce a stable monomer which
can be examined under electron microscopy.  Antibodies to the unique region
of desmoplakin I will be used to determine the location of this region on
the dimer by electron microscopy.  Fragments of desmoplakin I will be
produced by limited proteolysis, and fragments containing the unique region
will be identified by immunoblotting with this antibody.  Since
desmoplakins are phosphorylated and since evidence suggests that
phosphorylation may regulate interaction of some cytoskeletal proteins, the
ability of protein kinase C or Ca++calmodulin dependent kinase to
phosphorylate desmoplakins will be studied, and phosphorylation of
immunoprecipitated desmoplakins will be examined after exposure of
keratinocytes to the calcium switch or TPA.  The association of desmoplakin
I with keratin filaments will be assessed in a keratin binding assay, and
the ability of a purified 200 kd doublet to enhance binding of desmoplakin
I to purified keratin filaments will be tested.  These studies should
increase our knowledge of the role of specific protein interactions in
desmosome assembly.

## Key facts

- **NIH application ID:** 3155362
- **Project number:** 5R01AR025871-13
- **Recipient organization:** UNIV OF NORTH CAROLINA CHAPEL HILL
- **SAM.gov UEI:** D3LHU66KBLD5
- **Principal Investigator:** EDWARD J O'KEEFE
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 1991
- **Award amount:** $173,611
- **Award type:** 5
- **Project period:** 1979-07-01 → 1993-06-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/3155362

## Citation

> US National Institutes of Health, RePORTER application 3155362, DESMOSOME:  STRUCTURE AND FUNCTION (5R01AR025871-13). Retrieved via MORVS 2026-10-25 from https://api.morvs.ai/grant/nih/3155362. Licensed CC0.

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