HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by HATTON, J. P. Articles by SCHMITT, D. Search for Related Content PubMed PubMed Citation Articles by HATTON, J. P. Articles by SCHMITT, D.

The kinetics of translocation and cellular quantity of protein kinase C in human leukocytes are modified during spaceflight

JASON P. HATTON^*1, FRANÇOIS GAUBERT, MARIAN L. LEWIS, YANN DARSEL^§, PHILIPPE OHLMANN^*, JEAN-PIERRE CAZENAVE^* and DIDIER SCHMITT^*

^* INSERM U311, Etablissement de Transfusion Sanguine, 67065 Strasbourg;

INSERM U151, CHU Rangueil, 31054 Toulouse;

Wilson Hall, University of Alabama in Huntsville, Alabama 35899, USA; and

^§ Laboratoire D'Immunologie, CHU Rangueil, 31054 Toulouse Cedex, France

¹Correspondence: INSERM U311, Etablissement de Transfusion Sanguine, 67065 Strasbourg Cedex, France. E-mail: jason.hatton{at}etss.u-strasbg.fr

Protein kinase C (PKC) is a family of serine/threonine kinases that play an important role in mediating intracellular signal transduction in eukaryotes. U937 cells were exposed to microgravity during a space shuttle flight and stimulated with a radiolabeled phorbol ester ([³H]PDBu) to both specifically label and activate translocation of PKC from the cytosol to the particulate fraction of the cell. Although significant translocation of PKC occurred at all g levels, the kinetics of translocation in flight were significantly different from those on the ground. In addition, the total quantity of [³H]PDBu binding PKC was increased in flight compared to cells at 1 g on the ground, whereas the quantity in hypergravity (1.4 g) was decreased with respect to 1 g. Similarly, in purified human peripheral blood T cells the quantity of PKC varied in inverse proportion to the g level for some experimental treatments. In addition to these novel findings, the results confirm earlier studies which showed that PKC is sensitive to changes in gravitational acceleration. The mechanisms of cellular gravisensitivity are poorly understood but the demonstrated sensitivity of PKC to this stimulus provides us with a useful means of measuring the effect of altered gravity levels on early cell activation events.—Hatton, J. P., Gaubert, F., Lewis, M. L., Darsel, Y., Ohlmann, P., Cazenave, J.-P., Schmitt, D. The kinetics of translocation and cellular quantity of protein kinase C in human leukocytes are modified during spaceflight.

Key Words: microgravity • translocation

This article has been cited by other articles:

				M. Brownlee The Pathobiology of Diabetic Complications: A Unifying Mechanism Diabetes, June 1, 2005; 54(6): 1615 - 1625. [Full Text] [PDF]

				J. A. Felix, E. R. Dirksen, and M. L. Woodruff Physiology of a Microgravity Environment: Selected Contribution: PKC activation inhibits Ca2+ signaling in tracheal epithelial cells kept in simulated microgravity J Appl Physiol, August 1, 2000; 89(2): 855 - 864. [Abstract] [Full Text] [PDF]