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Zinc‐mediated regulation of the CKI1 ‐encoded choline kinase from yeast
Author(s) -
Soto Anibal,
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-b
Subject(s) - mutant , saccharomyces cerevisiae , biology , choline kinase , choline , biochemistry , reporter gene , cytosol , microbiology and biotechnology , kinase , phosphatidylcholine , enzyme , gene , gene expression , membrane , phospholipid
The CKI1 ‐encoded choline kinase catalyzes the committed step in the CDP‐choline pathway for the synthesis of phosphatidylcholine in Saccharomyces cerevisiae . The expression of CKI1 , as monitored by a P CKI1 ‐ lacZ reporter gene, was induced 8‐fold when zinc was depleted from the growth medium. This correlated with an increase (~ 2‐fold) in choline kinase enzyme activity. Analysis of a zrt1 Δ zrt2 Δ mutant defective in plasma membrane zinc transport indicated that the cytosolic level of zinc was responsible for this regulation. A promoter deletion analysis showed that a 349‐bp fragment, which contained a putative UAS ZRE sequence, was involved in this regulation. Direct interaction between purified GST‐Zap1p and the putative UAS ZRE sequences in the CKI1 promoter was demonstrated by electrophoretic mobility shift assays. Mutations in this putative UAS ZRE abolished the interaction with GST‐Zap1p. Current studies using zap1 Δ mutant cells address the physiological consequences of this interaction. Supported by NIH grant GM‐28140.