# MOLECULAR STUDIES OF FC RECEPTORS FOR IMMUNOGLOBULIN E

> **NIH NIH R01** · MEDICAL BIOLOGY INSTITUTE · 1989 · $165,466

## Abstract

The IgE receptor on mast cells and basophils (Fcepsilone R-I) is
directly involved in the IgE-mediated activation of these cells.
Recently, cDNA coding for the alpha-subunit of the rat Fcepsilone
R-I (Fcepsilone R-Ialpha) has been cloned.  RNA heterogeneity was
subsequently detected, suggesting the presence of variants of Fc
epsilone R-Ialpha, including the possible presence of intracellular
forms and secretory truncated forms of Fc epsilone R-Ialpha.  A new
IgE-binding protein, epsilone BP, was found to contain interesting
structural features, but its function is yet to be defined.  In
this research program, we will continue our studies of both Rc
epsilone R-I and epsilone BP.

First, structure-function relationship of rodent Fcepsilone R-I
alpha will be established.  Expression of cloned cDNA in mammalian
cells by gene transfection will be conducted.  Expression of both
the surface membrane-bound form and soluble form of the receptor
will be pursued.  Mutant Fc epsilone R-I alpha in normal rat mast
cells.  Various protein products predicted from the cDNA cloning
results, including the intracellular and secetory truncated forms
of Fcepsilone R-I alphs will be generated for structure-function
analysis to identify structural elements in FcepsiloneR-Ialphs that
are involved in binding to IgE.

Second, various forms of FcepsiloneR-Ialpha will be identified.
RNase protection analysis and polymerase chain reaction methodology
will be employed to identify various RNA forms related to
FcepsiloneR-Ialpha in normal rat mast cells.  Various protein
products predicted from the cDNA cloning results, including the
intracellular and secretory truncated forms of FcepsiloneR-Ialpha
will be detected in RBL cells.  Genomic DNA coding for mouse
FCepsiloneR-Ialpha will be cloned and used to extend the above
analysis to the mouse system.

Third, function of the newly defiend IgE-binding protein
(epsiloneBP) will be delineated.  Cell types expressing epsilone
and the location of epsilone in cells will be identified.  If it
is established that epsilone is not a cell suface receptor, its
role as a soluble protein, regulating IgE synthesis or histamine
release form mast cells and basophils will be explored.

The long-term goals of this research are: 1) establishment of
structure, function and regulation of key components of the IgE
system; and 2) development of therapeutic methods for the treatment
of human allergic disorders.

## Key facts

- **NIH application ID:** 3129134
- **Project number:** 2R01AI019747-07A1
- **Recipient organization:** MEDICAL BIOLOGY INSTITUTE
- **Principal Investigator:** FU-TONG LIU
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 1989
- **Award amount:** $165,466
- **Award type:** 2
- **Project period:** 1989-03-01 → 1994-02-28

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/3129134

## Citation

> US National Institutes of Health, RePORTER application 3129134, MOLECULAR STUDIES OF FC RECEPTORS FOR IMMUNOGLOBULIN E (2R01AI019747-07A1). Retrieved via MORVS 2026-10-24 from https://api.morvs.ai/grant/nih/3129134. Licensed CC0.

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