Calreticulin is an interleukin-3-sensitive calcium-binding protein in human basophil leukocytes
| Autor: | M. J. Lyngholm, A. H. Johnsen, Peter Oluf Schiøtz, M. Holm, Henrik Vendelbo Nielsen |
|---|---|
| Rok vydání: | 2001 |
| Předmět: |
Basophil cell
Immunology Gene Expression chemical and pharmacologic phenomena Basophil Cell Line chemistry.chemical_compound Calcium-binding protein medicine Immunology and Allergy Humans Electrophoresis Gel Two-Dimensional Gel electrophoresis biology Dose-Response Relationship Drug Calcium-Binding Proteins hemic and immune systems Molecular biology Basophils medicine.anatomical_structure chemistry Ribonucleoproteins biology.protein Secretagogue Calcium Interleukin-3 Signal transduction Calreticulin Histamine |
| Zdroj: | Allergy. 56(1) |
| ISSN: | 0105-4538 |
| Popis: | Background: IL-3 enhances basophil histamine release upon stimulation with any known secretagogue. The molecular mechanism behind this regulation is not known, although some observations suggest that IL-3 modulates the calcium part of the signal transduction mechanism. The inhibitory action of glucocorticoids on basophils can be reversed by stimulation with IL-3. Methods: Calcium-binding proteins in the basophil cell line KU812 were identified by two-dimensional gel electrophoresis, Calcium-overlay assay, N-terminal sequence analysis, and mass spectometry. The presence of the same proteins in purified human basophil leukocytes was established by comigration of KU812 and human basophil proteins on the two-dimensional gels. The expression of the calcium-binding proteins in the absence and presence of IL-3 and/or anti-IgE was determined by densitometric measurement of the spots on the two-dimensional gels. Results: Calreticulin was identified on the two-dimensional gel of KU812 proteins. A protein with exactly the same migration pattern was found on the gels of proteins from purified human basophils. Immunoblotting with a specific anti-human calreticulin antibody confirmed that this protein was calreticulin. Subsequent analysis showed that the expression of calreticulin in the basophils is upregulated twofold upon stimulation with rhIL-3, even in doses below those needed for enhancement of histamine release. Conclusions: The expression of calreticulin in human basophil leukocytes is regulated by IL-3. Calreticulin is known to modulate IP3-dependent Ca2+ influx in different cell systems, and calreticulin overexpression inhibits steroid-induced transcriptional activation. Therefore, modulation of calreticulin expression may be one mechanism by which IL-3 exerts its effects on human basophils. |
| Databáze: | OpenAIRE |
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