Signalling through Rho GTPases in microgravity (Rho Signalling).....................................................
Research Area: Cellular Biology
Expedition(s): 5
Principal Investigator(s): ● Betty V. Nusgens, University of Liège, Liège, Belgium
RESEARCH OBJECTIVES
The main objective of the Signalling through Rho GTPases in microgravity (Rho Signalling)
experiment is to analyze by immune-morphological procedures distinct cellular processes
(cytoskeleton and focal adhesions organization, GTPases translocation to the membrane,
translocation of activated signaling molecules) depending on Rho GTPases activity. The Rho
GTPases (RhoA, Rac1 & Cdc42) are molecular switches in the signaling pathways that relay the
information collected by most transmembrane receptors to modulate the mechanical and
phenotypic expression of the cells.
RESULTS
The Rho Signaling experiment was located in a vacuum-tight aluminum container (B-container),
providing 2 Ievels of containment for the plunger box unit (PBU) and their contents. Upon
inspection of the PBUs after landing, it turned out that 2 plungers had been correctly activated
to make the exchange of culture medium 6 hours after reaching 37°C in the incubator. Four
plungers had not been activated causing the loss of biological samples. Postflight debriefing
revealed that the B-container was disconnected and removed from the Aquarius, 5 minutes
before termination of the experiment just before the activation of the plungers. As such,
additional security should be applied in the future to prevent avoidable failure.
PUBLICATION(S)
Nusgens B, Lambert C, Lapiere C. Signaling through rho gtpases in microgravity (rho signaling)
on ISS (soyuz tma-1) Belgian soyuz mission “Odissea”. Microgravity Science and Technology.
September 2007;19(5-6):184-186. doi: 10.1007/BF02919478.
This investigation is complete and all results are published.