Diffusional mobility of Golgi proteins in membranes of living cells.
The mechanism by which Golgi membrane proteins are retained within the Golgi complex in the midst of a continuous flow of protein and lipid is not yet understood. The diffusional mobilities of mammalian Golgi membrane proteins fused with green fluorescent protein from Aequorea victoria were measured in living HeLa cells with the fluorescence photobleaching recovery technique. The diffusion coefficients ranged from 3 x 10(-9) square centimeters per second to 5 x 10(-9) square centimeters per second, with greater than 90 percent of the chimeric proteins mobile. Extensive lateral diffusion of the chimeric proteins occurred between Golgi stacks. Thus, the chimeras diffuse rapidly and freely in Golgi membranes, which suggests that Golgi targeting and retention of these molecules does not depend on protein immobilization.
Cole
N B
NB
Cell Biology and Metabolism Branch, National Institute of Child Health and Human Development, Building 18T, National Institutes of Health, Bethesda, MD 20892, USA.
Smith
C L
CL
Sciaky
N
N
Terasaki
M
M
Edidin
M
M
Lippincott-Schwartz
J
J
D017607:Aluminum Compounds / Q000494:pharmacology; D004058:Diffusion; D004721:Endoplasmic Reticulum / Q000378:metabolism; D005459:Fluorides / Q000494:pharmacology; D006056:Golgi Apparatus / Q000378:metabolism*; D049452:Green Fluorescent Proteins; D006367:HeLa Cells; D006801:Humans; D007425:Intracellular Membranes / Q000378:metabolism; D008164:Luminescent Proteins; D008361:Mannosidases / Q000378:metabolism*; D008565:Membrane Proteins / Q000378:metabolism*; D018613:Microscopy, Confocal; D009154:Mutation; D009237:N-Acetyllactosamine Synthase / Q000378:metabolism*; D018000:Receptors, Peptide / Q000235:genetics / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000378:metabolism
D017607:Aluminum Compounds; C064459:KDEL receptor; D008164:Luminescent Proteins; D008565:Membrane Proteins; D018000:Receptors, Peptide; D011993:Recombinant Fusion Proteins; D049452:Green Fluorescent Proteins; D009237:N-Acetyllactosamine Synthase; D008361:Mannosidases; C038829:mannosyl-oligosaccharide 1,3 - 1,6-alpha-mannosidase; D005459:Fluorides; C032311:aluminum fluoride