Increasing Phosphatidylinositol (4,5)-Bisphosphate Biosynthesis Affects Basal Signaling and Chloroplast Metabolism in Arabidopsis thaliana.

ABSTRACT: One challenge in studying the second messenger inositol(1,4,5)-trisphosphate (InsP₃) is that it is present in very low amounts and increases only transiently in response to stimuli. To identify events downstream of InsP₃, we generated transgenic plants constitutively expressing the high specific activity, human phosphatidylinositol 4-phosphate 5-kinase Iα (HsPIPKIα). PIP5K is the enzyme that synthesizes phosphatidylinositol (4,5)-bisphosphate (PtdIns(4,5)P₂); this reaction is flux limiting in InsP₃ biosynthesis in plants. Plasma membranes from transgenic Arabidopsis expressing HsPIPKIα had 2-3 fold higher PIP5K specific activity, and basal InsP₃ levels in seedlings and leaves were >2-fold higher than wild type. Although there was no significant difference in photosynthetic electron transpo

SUBMITTER: Im YJ 

PROVIDER: S-EPMC4844314 | biostudies-literature | 2014 Jan

REPOSITORIES: biostudies-literature