UNASSIGNED: Autophagy is a highly regulated pathway that selectively degrades cellular constituents such as protein aggregates and excessive or damaged organelles. This transport route is characterized by the engulfment of the targeted cargo by autophagosomes. The formation of these double-membrane vesicles requires the covalent conjugation of the ubiquitin-like protein @entity46874 to @entity3633 (PE). However, the origin of PE and the regulation of lipid flux required for autophagy remain poorly understood. Using a genetic screen, we found that the temperature-sensitive growth and intracellular membrane organization defects of @entity68715 -174 and @entity68715 - @entity18824 mutants are suppressed by deletion of essential autophagy genes such as @entity50289 or @entity68716 . @entity68715 encodes an @entity2230 transferase, which uses PE as a precursor for an essential step in the synthesis of the @entity4495 (GPI) anchor used to link a subset of plasma membrane proteins to lipid bilayers. Similar to the deletion of @entity68717 , a gene encoding the enzyme converting PE to @entity2434 (PC), deletion of @entity68716 was able to restore lipidation and plasma membrane localization of the GPI-anchored protein @entity62623 , and normal organization of intracellular membranes. Conversely, overexpression of @entity68717 was lethal in @entity68715 -174 cells grown at restrictive temperature. Quantitative lipid analysis revealed that PE levels are substantially reduced in the @entity68715 -174 mutant, but can be restored by deletion of @entity68716 or @entity68717 . Taken together, these data suggest that autophagy competes for a common PE pool with major cellular PE-consuming pathways such as the GPI-anchor and PC synthesis, highlighting the possible interplay between these pathways and the existence of signals that may coordinate PE flux.

Autophagy Competes for a Common XXXX Pool with Major Cellular PE-Consuming Pathways in Saccharomyces cerevisiae.

@entity2230 :: ('MESH:C005448', 'Chemical') :: ['ethanolamine phosphate'] @entity18824 :: ('p|SUB|P|301|L', 'ProteinMutation') :: ['P301L'] @entity2434 :: ('MESH:D010713', 'Chemical') :: ['phosphatidylcholine'] @entity46874 :: ('852200(Tax:4932)', 'Gene') :: ['Atg8'] @entity3633 :: ('MESH:C483858', 'Chemical') :: ['phosphatidylethanolamine'] @entity50289 :: ('852695(Tax:4932)', 'Gene') :: ['ATG1'] @entity68717 :: ('853061(Tax:4932)', 'Gene') :: ['Cho2', 'CHO2'] @entity4495 :: ('MESH:D017261', 'Chemical') :: ['glycosylphosphatidylinositol'] @entity68715 :: ('853690(Tax:4932)', 'Gene') :: ['mcd4', 'MCD4'] @entity62623 :: ('855355(Tax:4932)', 'Gene') :: ['Gas1'] @entity68716 :: ('856576(Tax:4932)', 'Gene') :: ['ATG7']
@entity3633 :: (MESH:C483858,Chemical) :: ['Phosphatidylethanolamine']
