Regulation of sphingolipid synthesis by the G1/S transcription factor Swi4.

SBF (Swi4/Swi6 Binding Factor) complex is a crucial regulator of G1/S transition in Saccharomyces cerevisiae. Here, we show that SBF complex is required for myriocin resistance, an inhibitor of sphingolipid synthesis. This phenotype was not shared with MBF complex mutants nor with deletion of the Swi4p downstream targets, CLN1/CLN2.

Induction of triacylglycerol synthesis in yeast by cell cycle arrest.

In this study, we found that cell cycle arrest induced by alpha-factor mating pheromone (G1), hydroxyurea (S) or nocodazole (G2/M) was associated to increased lipid droplet (LD) content. To identify novel cell cycle genes involved in LD homeostasis, we screened a deletion library for strains with altered LD levels. Among the mutants related to mitotic cell cycle, we found 24 hits that displayed a significantly higher LD content.

Biological study of Trypanosoma caninum under co-culture with different feeder layer cells.

Trypanosoma caninum is a parasite isolated from domestic dogs, of which several biological aspects remain unknown, including evolutive forms found in vertebrate hosts. The objective of this study was to evaluate co-cultures of T. caninum with different cell lines as feeder layers to monitor the differentiation process and investigate infective potential.

A Chemogenomic Screen Reveals Novel Snf1p/AMPK Independent Regulators of Acetyl-CoA Carboxylase.

Acetyl-CoA carboxylase (Acc1p) is a key enzyme in fatty acid biosynthesis and is essential for cell viability. To discover new regulators of its activity, we screened a Saccharomyces cerevisiae deletion library for increased sensitivity to soraphen A, a potent Acc1p inhibitor. The hits identified in the screen (118 hits) were filtered using a chemical-phenotype map to exclude those associated with pleiotropic drug resistance.

TORC1 inhibition induces lipid droplet replenishment in yeast.

Lipid droplets (LDs) are intracellular structures that regulate neutral lipid homeostasis. In mammals, LD synthesis is inhibited by rapamycin, a known inhibitor of the mTORC1 pathway. In Saccharomyces cerevisiae, LD dynamics are modulated by the growth phase; however, the regulatory pathways involved are unknown.

A new fluorescence-based method identifies protein phosphatases regulating lipid droplet metabolism.

In virtually every cell, neutral lipids are stored in cytoplasmic structures called lipid droplets (LDs) and also referred to as lipid bodies or lipid particles. We developed a rapid high-throughput assay based on the recovery of quenched BODIPY-fluorescence that allows to quantify lipid droplets. The method was validated by monitoring lipid droplet turnover during growth of a yeast culture and by screening a group of strains deleted in genes known to be involved in lipid metabolism.