Disease relevance of ATPIS1

• Functional assays, performed by overexpression of the plant cDNA in Escherichia coli, a bacteria which lacks phosphatidylinositol and phosphatidylinositol synthase activity, showed that the plant protein induced the accumulation of phosphatidylinositol in the bacterial cells [1].
• The pis1 mutation conferred hypersensitivity to both NPA and TIBA but not to HFCA [2].

High impact information on ATPIS1

• PIS1, a negative regulator of the action of auxin transport inhibitors in Arabidopsis thaliana [2].
• In order to clarify the mechanism underlying the polar auxin transport system, the pis1 mutant in Arabidopsis thaliana that is hypersensitive to N-1-naphthylphthalamic acid (NPA), an auxin transport inhibitor was isolated and characterized [2].
• Whereas the pis1 mutant is normally sensitive to phytohormones, auxins, cytokinin and ethylene precursor, this mutant is hypersensitive to NPA over the broad spectrum of its effects such as growth of seedlings, root elongation, root gravitropism, root phototropism and root curling [2].
• The cloning and identification of full-length cDNA fragments coding for the Brassica napus phosphatidylinositol-specific phospholipase C2 (BnPLC2), phosphatidylinositol 3-kinase (BnVPS34) and phosphatidylinositol synthase (BnPtdIns S1) is described [3].
• PI is synthesized from CDP-diacylglycerol (CDP-DG) and myo-inositol by phosphatidylinositol synthase (PI synthase, EC 2.7.8.11) [4].

Anatomical context of ATPIS1

• AtPIS1 functionally complements a mutant of S. cerevisiae with a lesion in PI synthase, and recombinant AtPIS1 protein present in yeast membranes strongly depends on the two principal substrates, myo-inositol and CDP-DG, and requires Mg2+ ions for full activity [4].

Associations of ATPIS1 with chemical compounds

• This result indicates that the pis1 mutant is specifically affected in the polar auxin transport system [2].

References