<p>1L-myo-Inositol-1-phosphate synthase (<db_xref db="EC" dbkey="5.5.1.4"/>) catalyzes the conversion of D-glucose 6-phosphate to 1L-myo-inositol-1-phosphate, the first committed step in the production of all inositol-containing compounds, including phospholipids, either directly or by salvage. The enzyme exists in a cytoplasmic form in a wide range of plants, animals, and fungi. It has also been detected in several bacteria and a chloroplast form is observed in alga and higher plants. Inositol phosphates play an important role in signal transduction.</p><p> In <taxon tax_id="4932">Saccharomyces cerevisiae</taxon> (Baker's yeast), the transcriptional regulation of the INO1 gene has been studied in detail [<cite idref="PUB00005654"/>] and its expression is sensitive to the availability of phospholipid precursors as well as growth phase. The regulation of the structural gene encoding 1L-myo-inositol-1-phosphate synthase has also been analyzed at the transcriptional level in the aquatic angiosperm, <taxon tax_id="29656">Spirodela polyrrhiza</taxon> (Giant duckweed) and the halophyte, <taxon tax_id="3544">Mesembryanthemum crystallinum</taxon> (Common ice plant) [<cite idref="PUB00006393"/>].</p>