The spatial organization of lipid synthesis in the yeast Saccharomyces cerevisiae derived from large scale green fluorescent protein tagging and high resolution microscopy.
The localization pattern of proteins involved in lipid metabolism in the yeast Saccharomyces cerevisiae was determined using C-terminal green fluorescent protein tagging and high resolution confocal laser scanning microscopy. A list of 493 candidate proteins ( approximately 9% of the yeast proteome) was assembled based on proteins of known function in lipid metabolism, their interacting proteins, proteins defined by genetic interactions, and regulatory factors acting on selected genes or proteins. Overall 400 (81%) transformants yielded a positive green fluorescent protein signal, and of these, 248 (62% of the 400) displayed a localization pattern that was not cytosolic. Observations for many proteins with known localization patterns were consistent with published data derived from cell fractionation or large scale localization approaches. However, in many cases, high resolution microscopy provided additional information that indicated that proteins distributed to multiple subcellular locations. The majority of tagged enzymes localized to the endoplasmic reticulum (91), but others localized to mitochondria (27), peroxisomes (17), lipid droplets (23), and vesicles (53). We assembled enzyme localization patterns for phospholipid, sterol, and sphingolipid biosynthetic pathways and propose a model, based on enzyme localization, for concerted regulation of sterol and sphingolipid metabolism that involves shuttling of key enzymes between endoplasmic reticulum, lipid droplets, vesicles, and Golgi.
Natter
Klaus
K
Institute of Molecular Biosciences, Spezialforschungsbereich Biomembrane Research Center, University of Graz, Schubertstr. 1, A8010 Graz, Austria.
Leitner
Peter
P
Faschinger
Alexander
A
Wolinski
Heimo
H
McCraith
Stephen
S
Fields
Stanley
S
Kohlwein
Sepp D
SD
D015415:Biomarkers / Q000378:metabolism*; D004721:Endoplasmic Reticulum / Q000378:metabolism / Q000648:ultrastructure; D049452:Green Fluorescent Proteins / Q000378:metabolism*; D050356:Lipid Metabolism; D018613:Microscopy, Confocal; D008928:Mitochondria / Q000378:metabolism / Q000648:ultrastructure; D020675:Peroxisomes / Q000378:metabolism / Q000648:ultrastructure; D012441:Saccharomyces cerevisiae / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000378:metabolism*; D013347:Subcellular Fractions / Q000648:ultrastructure
D015415:Biomarkers; D029701:Saccharomyces cerevisiae Proteins; D049452:Green Fluorescent Proteins