Synchronous intra-Golgi transport induces the release of Ca2+ from the Golgi apparatus.
The mechanisms of secretory transport through the Golgi apparatus remain an issue of debate. The precise functional importance of calcium ions (Ca(2+)) for intra-Golgi transport has also been poorly studied. Here, using different approaches to measure free Ca(2+) concentrations in the cell cytosol ([Ca(2+)](cyt)) and inside the lumen of the Golgi apparatus ([Ca(2+)](GA)), we have revealed transient increases in [Ca(2+)](cyt) during the late phase of intra-Golgi transport that are concomitant with a decline in the maximal [Ca(2+)](GA) restoration ability. Thus, this redistribution of Ca(2+) from the Golgi apparatus into the cytosol during the movement of cargo through the Golgi apparatus appears to have a role in intra-Golgi transport, and mainly in the late Ca(2+)-dependent phase of SNARE-regulated fusion of Golgi compartments.
Micaroni
Massimo
M
Department of Cell Biology and Oncology, Consorzio Mario Negri Sud, 66030 Santa Maria Imbaro (CH), Italy. m.micaroni@imb.uq.edu.au
Perinetti
Giuseppe
G
Di Giandomenico
Daniele
D
Bianchi
Katiuscia
K
Spaar
Alexander
A
Mironov
Alexander A
AA
D001692:Biological Transport; D002118:Calcium / Q000378:metabolism*; D020013:Calcium Signaling; D002478:Cells, Cultured; D003600:Cytosol / Q000378:metabolism*; D005347:Fibroblasts / Q000378:metabolism; D006056:Golgi Apparatus / Q000378:metabolism*; D006367:HeLa Cells; D006801:Humans; D012867:Skin / Q000166:cytology / Q000378:metabolism; D013347:Subcellular Fractions
D002118:Calcium