A traffic-activated Golgi-based signalling circuit coordinates the secretory pathway.
As with other complex cellular functions, intracellular membrane transport involves the coordinated engagement of a series of organelles and machineries; however, the molecular basis of this coordination is unknown. Here we describe a Golgi-based signalling system that is activated by traffic and is involved in monitoring and balancing trafficking rates into and out of the Golgi complex. We provide evidence that the traffic signal is due to protein chaperones that leave the endoplasmic reticulum and reach the Golgi complex where they bind to the KDEL receptor. This initiates a signalling reaction that includes the activation of a Golgi pool of Src kinases and a phosphorylation cascade that in turn activates intra-Golgi trafficking, thereby maintaining the dynamic equilibrium of the Golgi complex. The concepts emerging from this study should help to understand the control circuits that coordinate high-order cellular functions.
Pulvirenti
Teodoro
T
Laboratory of Membrane Traffic, Department of Cell Biology and Oncology, Consorzio Mario Negri Sud, 66030 Santa Maria Imbaro (Chieti), Italy.
Giannotta
Monica
M
Capestrano
Mariagrazia
M
Capitani
Mirco
M
Pisanu
Antonio
A
Polishchuk
Roman S
RS
San Pietro
Enrica
E
Beznoussenko
Galina V
GV
Mironov
Alexander A
AA
Turacchio
Gabriele
G
Hsu
Victor W
VW
Sallese
Michele
M
Luini
Alberto
A
D000818:Animals; D001692:Biological Transport; D002460:Cell Line; D006056:Golgi Apparatus / Q000378:metabolism*; D006801:Humans; D008854:Microscopy, Electron; D008856:Microscopy, Fluorescence; D018832:Molecular Chaperones / Q000378:metabolism; D010766:Phosphorylation; D021381:Protein Transport; D018000:Receptors, Peptide / Q000378:metabolism; D015398:Signal Transduction; D019061:src-Family Kinases / Q000378:metabolism
C064459:KDEL receptor; D018832:Molecular Chaperones; D018000:Receptors, Peptide; D019061:src-Family Kinases