Cell size is regulated by phospholipids and not by storage lipids in Saccharomyces cerevisiae

Abstract

Cell size and morphology are key adaptive features that influence almost all aspects of cellular physiology such as cell cycle and lipid metabolism. Here we report the role of a transcription factor Suppressor Phenotype of Ty elements insertion 10 (SPT10) of Saccharomyces cerevisiae in regulating cell cycle, cell size and lipid metabolism in concert, in addition to its defined role of histone gene expression. Morphological and biochemical analyses of spt10Δ strain show an abnormal cell size, cell cycle and lipid levels. The expression of Spt10p in spt10Δ strain helps the cell revert to typical wild-type phenotypes. SPT10 controls lipid metabolism by negatively regulating the expression of lipid biosynthetic genes, and positively regulating the expression of the lipid hydrolyzing genes. Spt10p helps in maintaining the cell size by regulating the amount of carbon flux into the phospholipid constituents of the cell membranes. On the contrary, storage lipids have no role in regulating the cell size. An exogenous supply of phosphatidic acid increases the cell size, proving the positive impact of the phospholipids on cell size modulation. SPT10 affects cell cycle, cell size and lipid metabolism by an orchestrated transcriptional regulation of the corresponding genes.

Impairment of transcription factor Gcr1p binding motif perturbs OPI3 transcription in Saccharomyces cerevisiae

“…In yeast several transcription factors contribute to OPI3 regulation 5,20,21 and in silico analysis (using YEAS-TRACT promoter database) revealed potential binding site for Gcr1p "CTTCC" (CT box) located at −783, −580, −523, −487, −265, −248 positions (numbering based on the location of ATG, the translation initiation codon) in OPI3 promoter (Figure 1A). To elucidate whether transcription factor Gcr1p is involved in OPI3 transcription, we initially examined the in vivo occupancy of Gcr1p on the OPI3 promoter, using ChIP assay in gcr1Δ cells harboring pRS315-GCR1 cells.…”

“…Sin3p negatively regulates OPI3 expression through the UAS INO element and the PC levels were elevated in sin3∆ cells 5,20 . The transcription factor Spt10p (Suppressor Phenotype of Ty element insertion 10) negatively regulates OPI3 expression, and its deletion elevates the PC level thereby disturbing the phospholipid and neutral lipid metabolism 21 …”

“…5,20 The transcription factor Spt10p (Suppressor Phenotype of Ty element insertion 10) negatively regulates OPI3 expression, and its deletion elevates the PC level thereby disturbing the phospholipid and neutral lipid metabolism. 21 An essential function of PC is to form a constant matrix for cellular membranes and serves as a reservoir for signaling molecules. PC homeostasis maintains membrane shape, stability, and activity, 22,23 is vital for maintenance of health, [24][25][26] and its depletion increases Ca 2+ influx, 27,28 affects cell growth, 22 and activates UPRE.…”

The Spt10 GNAT Superfamily Protein Modulates Development, Cell Cycle Progression and Virulence in the Fungal Insect Pathogen, Beauveria bassiana

“…However, it has been suggested that these effects are indirect via (direct) regulation of a far more restricted number of genes, potentially limited only to the regulation of core histone genes [27]. Regardless of the mechanism, Spt10 contributes to a cell cycle regulating oscillator complex, affects cell size via mobilization of phospholipids, and functions (cooperating with histone H2A) in the regulation of metallothionein genes [28][29][30]. An intriguing feature of Spt10 is the presence of a conserved histone acetyltransferase (HAT) domain similar to that of Gcn5 [15].…”

Diacylglycerol kinase alleviates autophagic degradation of the endoplasmic reticulum in SPT10‐deficient yeast to enhance triterpene biosynthesis

“…The deletion of SPT10 ( spt10Δ ) is not lethal; however, its phenotype exhibits an abnormal cell morphology with a reduced growth rate [15]. In a recent study, the spt10∆ strain exhibited high levels of endogenous PA and PLs [16]. We hypothesised that spt10Δ , a strain that accumulates more endogenous PLs, would result in high endogenous MEV/ERG activity.…”