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EKI1 ‐dependent regulation of phospholipid synthesis by mRNA stability
Author(s) -
Choi Hyeon Son,
Carman George M.
Publication year - 2006
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.20.4.a85-a
Subject(s) - diacylglycerol kinase , messenger rna , mutant , phospholipid , ethanolamine , enzyme , phosphatidylserine , saccharomyces cerevisiae , biochemistry , second messenger system , biology , microbiology and biotechnology , protein kinase c , chemistry , yeast , gene , membrane
In the yeast Saccharomyces cerevisiae , membrane phospholipids are synthesized by complementary (CDP‐diacylglycerol and Kennedy) pathways. Cells compensate for a block (e.g., cki1 Δ eki1 Δ) in the Kennedy pathway by increasing the expression of CDP‐diacylglycerol pathway enzyme activities. For the CHO1 ‐encoded phosphatidylserine synthase, the enzyme that catalyzes the committed step in the pathway, activity is regulated in cki1 Δ eki1 Δ double mutant cells by increases in mRNA and enzyme protein. A major component of this regulation is a dramatic increase in transcript stability. An analysis of this regulation in eki1 Δ and cki1 Δ single mutants showed that a block in the CDP‐ethanolamine branch of the Kennedy pathway increased CHO1 mRNA stability whereas a block in the CDP‐choline branch exhibited normal rates of decay. A decay analysis of mutants ( eki1 Δ, ect1 Δ, and ept1 Δ) defective in each step of the CDP‐ethanolamine branch of the pathway showed that the block in the EKI1 ‐encoded ethanolamine kinase was the only step in the pathway that regulated CHO1 mRNA stability. Studies to examine the mechanism for CHO1 mRNA degradation are currently being investigated. Supported by NIH grant GM 50679.