Golgi inheritance in mammalian cells is mediated through endoplasmic reticulum export activities.
Golgi inheritance during mammalian cell division occurs through the disassembly, partitioning, and reassembly of Golgi membranes. The mechanisms responsible for these processes are poorly understood. To address these mechanisms, we have examined the identity and dynamics of Golgi proteins within mitotic membranes using live cell imaging and electron microscopy techniques. Mitotic Golgi fragments, seen in prometaphase and telophase, were found to localize adjacent to endoplasmic reticulum (ER) export domains, and resident Golgi transmembrane proteins cycled rapidly into and out of these fragments. Golgi proteins within mitotic Golgi haze-seen during metaphase-were found to redistribute with ER markers into fragments when the ER was fragmented by ionomycin treatment. The temperature-sensitive misfolding mutant ts045VSVG protein, when localized to the Golgi at the start of mitosis, became trapped in the ER at the end of mitosis in cells shifted to 40 degrees C. Finally, reporters for Arf1 and Sar1 activity revealed that Arf1 and Sar1 undergo sequential inactivation during mitotic Golgi breakdown and sequential reactivation upon Golgi reassembly at the end of mitosis. Together, these findings support a model of mitotic Golgi inheritance that involves inhibition and subsequent reactivation of cellular activities controlling the cycling of Golgi components into and out of the ER.
Altan-Bonnet
Nihal
N
Cell Biology and Metabolism Branch, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA.
Sougrat
Rachid
R
Liu
Wei
W
Snapp
Erik L
EL
Ward
Theresa
T
Lippincott-Schwartz
Jennifer
J
D020823:ADP-Ribosylation Factor 1 / Q000032:analysis / Q000378:metabolism; D000818:Animals; D002417:Cattle; D002455:Cell Division / Q000502:physiology*; D004721:Endoplasmic Reticulum / Q000187:drug effects / Q000502:physiology* / Q000648:ultrastructure; D020558:GTP Phosphohydrolases / Q000032:analysis / Q000378:metabolism; D005700:Galactosyltransferases / Q000032:analysis; D006056:Golgi Apparatus / Q000187:drug effects / Q000502:physiology* / Q000648:ultrastructure; D015759:Ionomycin / Q000494:pharmacology; D007476:Ionophores / Q000494:pharmacology; D008164:Luminescent Proteins / Q000032:analysis; D008856:Microscopy, Fluorescence; D008954:Models, Biological; D015739:Nocodazole / Q000494:pharmacology; D051381:Rats; D011993:Recombinant Fusion Proteins / Q000032:analysis
D007476:Ionophores; D008164:Luminescent Proteins; D011993:Recombinant Fusion Proteins; D015759:Ionomycin; D005700:Galactosyltransferases; D020558:GTP Phosphohydrolases; D020823:ADP-Ribosylation Factor 1; D015739:Nocodazole