Expression of a long variant of CRACR2A that belongs to the Rab GTPase protein family in endothelial cells.
Bottom Line: Unexpectedly, short interfering RNA designed to deplete CRACR2A had no effect on CRAC channels in endothelial cells but reduced the abundance of a protein with about twice the mass of CRACR2A.It made a positive contribution to endothelial tube formation.The data suggest that endothelial cells contain a long variant of CRACR2A which is an EF-hand-containing Rab protein that lacks impact on CRAC channels.
Affiliation: School of Medicine, University of Leeds, Leeds LS2 9JT, UK.Show MeSH
Related in: MedlinePlus
Mentions: Intracellular Ca2+ was recorded from human umbilical vein endothelial cells (HUVECs) to observe Ca2+ release evoked by thapsigargin (TG) in the absence of extracellular Ca2+ and then CRAC channel-mediated Ca2+ entry as extracellular Ca2+ was added back (Fig. 1A). Unexpectedly, transfection with short interfering RNA (siRNA) targeted to CRACR2A failed to affect Ca2+ release or Ca2+ entry (Fig. 1A and B). In contrast, siRNA targeted to Orai1 suppressed Ca2+ entry but not Ca2+ release, consistent with Orai1-dependent CRAC channels mediating Ca2+ entry (Fig. 1C and D). The data suggest that CRACR2A is unimportant for CRAC channels in these cells.
Affiliation: School of Medicine, University of Leeds, Leeds LS2 9JT, UK.