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Opi1p relocalizaton in response to inositol in scs2Δpct1Δ mutant
Author(s) -
Chang Yu-Fang,
Gaspar Maria L.,
Henry Susan A.
Publication year - 2012
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.26.1_supplement.790.15
Subject(s) - inositol , mutant , biosynthesis , phospholipid , repressor , phosphatidic acid , biochemistry , phenotype , auxotrophy , biology , phosphatidylcholine , enzyme , yeast , saccharomyces cerevisiae , microbiology and biotechnology , chemistry , gene , membrane , gene expression , receptor
Phosphatidic acid (PA) is a signaling lipid that plays an important role in regulating phospholipid biosynthetic genes such as INO1 . PA levels in yeast can be manipulated by shifting cells from inositol‐containing medium to inositol‐lacking medium or deletion of enzymes involved in biosynthesis of phosphatidylcholine (PC). Scs2p, a homolog of VAP, is an integral membrane protein that targets to the ER and nuclear membranes. Scs2p contains a motif (FFAT) that binds to Opi1p, a repressor of phospholipid biosynthesis which binds to PA. The scs2 Δ mutant exhibits weak inositol auxotrophy (Ino‐phenotype) at 30°C. Co‐deletion of enzymes in Kennedy pathway for PC biosynthesis had been shown to rescue this Ino‐phenotype (Kagiwada and Zen, 2003). We have now shown that pct1 Δ not only rescues the Ino‐phenotype of scs2 Δ, it also rescues the choline sensitivity of scs2 Δ at both 30 °C and 37 °C. The de‐repression of INO1 gene in the scs2 Δ pct1 Δ strain was accompanied by Opi1p‐GFP relocalization to punctate structures resembling lipid droplets when the cells were grown in the absence of inositol.