Secretory traffic triggers the formation of tubular continuities across Golgi sub-compartments.
The organization of secretory traffic remains unclear, mainly because of the complex structure and dynamics of the secretory pathway. We have thus studied a simplified system, a single synchronized traffic wave crossing an individual Golgi stack, using electron tomography. Endoplasmic-reticulum-to-Golgi carriers join the stack by fusing with cis cisternae and induce the formation of intercisternal tubules, through which they redistribute their contents throughout the stack. These tubules seem to be pervious to Golgi enzymes, whereas Golgi vesicles are depleted of both enzymes and cargo. Cargo then traverses the stack without leaving the cisternal lumen. When cargo exits the stack, intercisternal connections disappear. These findings provide a new view of secretory traffic that includes dynamic intercompartment continuities as key players.
Trucco
Alvar
A
Department of Cell Biology and Oncology, Consorzio Mario Negri Sud, 66030 Santa Maria Imbaro, Chieti, Italy.
Polishchuk
Roman S
RS
Martella
Oliviano
O
Di Pentima
Alessio
A
Fusella
Aurora
A
Di Giandomenico
Daniele
D
San Pietro
Enrica
E
Beznoussenko
Galina V
GV
Polishchuk
Elena V
EV
Baldassarre
Massimiliano
M
Buccione
Roberto
R
Geerts
Willie J C
WJ
Koster
Abraham J
AJ
Burger
Koert N J
KN
Mironov
Alexander A
AA
Luini
Alberto
A
D001692:Biological Transport; D002451:Cell Compartmentation; D002460:Cell Line; D004721:Endoplasmic Reticulum / Q000648:ultrastructure; D006056:Golgi Apparatus / Q000648:ultrastructure*; D008854:Microscopy, Electron