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The role of the cytosolic free Ca2+ transient for fMet-Leu-Phe induced actin polymerization in human neutrophils.
- Source :
-
European journal of cell biology [Eur J Cell Biol] 1986 Dec; Vol. 42 (2), pp. 338-43. - Publication Year :
- 1986
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Abstract
- We have addressed the important question as to if and how the cytosolic free Ca2+ concentration, [Ca2+]i, is involved in fMet-Leu-Phe induced actin polymerization in human neutrophils. Stimulation of human neutrophils with the chemotactic peptide (10(-7) M), known to result in a prompt rise of the [Ca2+]i to above 500 nM, also induced a rapid decrease of monomeric actin, G-actin, content (to 35% of basal) and increase of filamentous actin, F-actin, content (to 320% of basal). A reduction of the fMet-Leu-Phe induced [Ca2+]i transient to about 250 nM, resulted in a less pronounced decrease of G-actin content (to 80% of basal) and increase of F-actin content (to 235% of basal). A total abolishment of the chemotactic peptide induced [Ca2+]i rise, still led to a decrease of the G-actin content (to 85% of basal) and increase of F-actin (to 200% of basal). These results indicate that the [Ca2+]i rise is not an absolute requirement, but has a modulating role for the fMet-Leu-Phe induced actin polymerization. Another possible intracellular candidate for fMet-Leu-Phe induced actin polymerization is protein kinase C. However, direct activation of protein kinase C by phorbol 12-myristate 13-acetate (PMA) only resulted in a minor increase of F-actin content. The recent hypothesis that a metabolite of the polyphosphoinositide cycle, independently of [Ca2+]i and protein kinase C, is responsible for actin polymerization agrees well with these results and by the fact that preexposure to pertussis toxin totally abolished a subsequent increase of F-actin content induced by fMet-Leu-Phe.
- Subjects :
- Actin Cytoskeleton physiology
Cells, Cultured
Humans
Neutrophils drug effects
Pertussis Toxin
Polymers
Protein Kinase C physiology
Tetradecanoylphorbol Acetate pharmacology
Virulence Factors, Bordetella pharmacology
Actin Cytoskeleton drug effects
Actins physiology
Calcium physiology
Chemotaxis, Leukocyte drug effects
Cytoskeleton drug effects
N-Formylmethionine Leucyl-Phenylalanine pharmacology
Neutrophils ultrastructure
Subjects
Details
- Language :
- English
- ISSN :
- 0171-9335
- Volume :
- 42
- Issue :
- 2
- Database :
- MEDLINE
- Journal :
- European journal of cell biology
- Publication Type :
- Academic Journal
- Accession number :
- 3816821