GM130 and GRASP65-dependent lateral cisternal fusion allows uniform Golgi-enzyme distribution.
The mammalian Golgi apparatus exists as stacks of cisternae that are laterally linked to form a continuous membrane ribbon, but neither the molecular requirements for, nor the purpose of, Golgi ribbon formation are known. Here, we demonstrate that ribbon formation is mediated by specific membrane-fusion events that occur during Golgi assembly, and require the Golgi proteins GM130 and GRASP65. Furthermore, these GM130 and GRASP65-dependent lateral cisternal-fusion reactions are necessary to achieve uniform distribution of enzymes in the Golgi ribbon. The membrane continuity created by ribbon formation facilitates optimal processing conditions in the biosynthetic pathway.
Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, PA 15213, USA.
Manojkumar A
MA
Puthenveedu
Collin
C
Bachert
Sapna
S
Puri
Frederick
F
Lanni
Adam D
AD
Linstedt
D001324:Autoantigens; D006031:Glycosylation; D006056:Golgi Apparatus / Q000201:enzymology* / Q000502:physiology* / Q000648:ultrastructure; D000077614:Golgi Matrix Proteins; D006367:HeLa Cells; D006801:Humans; D007425:Intracellular Membranes / Q000502:physiology* / Q000648:ultrastructure; D008561:Membrane Fusion; D008565:Membrane Proteins / Q000235:genetics / Q000502:physiology*; D046529:Microscopy, Electron, Transmission; D021381:Protein Transport; D034741:RNA, Small Interfering / Q000235:genetics
D001324:Autoantigens; C108705:GORASP1 protein, human; D000077614:Golgi Matrix Proteins; C097741:Golgin subfamily A member 2; D008565:Membrane Proteins; D034741:RNA, Small Interfering