Cytosolic Ca2+ signals depending on the functional state of the Golgi in HeLa cells.
The Golgi apparatus is, like the endoplasmic reticulum, an inositol-1,4,5-trisphosphate-sensitive Ca2+ store, but its role in setting up Ca2+ signals is not well understood. We have now measured histamine-induced Ca2+ signals in HeLa cells pretreated with brefeldin A, a fungal metabolite that leads to the fragmentation and subsequent disappearance of the Golgi apparatus by its reabsorption within the endoplasmic reticulum. Ca2+ responses in which the free cytoplasmic Ca2+ concentration returned to resting levels during the histamine stimulation (mainly baseline Ca2+ oscillations or a single Ca2+ peak) occurred more often in brefeldin A pretreated cells, resulting in a lower Ca2+ plateau in population measurements. The latencies before the onset of the Ca2+ signals were longer after brefeldin A pretreatment. These results suggest that the integrity of the Golgi apparatus contributes to the shaping of intracellular Ca2+ signals.
Vanoevelen
J
J
Afdeling Fysiologie, K.U. Leuven Campus Gasthuisberg O/N-802, Herestraat 49, B-3000 Leuven, Belgium. Jo.Vanoevelen@med.kuleuven.be
Raeymaekers
L
L
Dode
L
L
Parys
J B
JB
De Smedt
H
H
Callewaert
G
G
Wuytack
F
F
Missiaen
L
L
D020126:Brefeldin A / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism*; D020013:Calcium Signaling / Q000187:drug effects / Q000502:physiology*; D003600:Cytosol / Q000502:physiology*; D005455:Fluorescent Antibody Technique; D006056:Golgi Apparatus / Q000187:drug effects / Q000502:physiology*; D006367:HeLa Cells / Q000648:ultrastructure; D006632:Histamine / Q000494:pharmacology; D006801:Humans; D011930:Reaction Time / Q000187:drug effects
D020126:Brefeldin A; D006632:Histamine; D002118:Calcium