Phagocytic and pinocytic uptake of cholesterol in Tetrahymena thermophila impact differently on gene regulation for sterol homeostasis.

ABSTRACT: The ciliate Tetrahymena thermophila can either synthesize tetrahymanol or when available, assimilate and modify sterols from its diet. This metabolic shift is mainly driven by transcriptional regulation of genes for tetrahymanol synthesis (TS) and sterol bioconversion (SB). The mechanistic details of sterol uptake, intracellular trafficking and the associated gene expression changes are unknown. By following cholesterol incorporation over time in a conditional phagocytosis-deficient mutant, we found that although phagocytosis is the main sterol intake route, a secondary endocytic pathway exists. Different expression patterns for TS and SB genes were associated with these entry mechanisms. Squalene synthase was down-regulated by a massive cholesterol intake only attainable by phagocytosis-p

SUBMITTER: Hernandez J 

PROVIDER: S-EPMC8079401 | biostudies-literature | 2021 Apr

REPOSITORIES: biostudies-literature