Pleckstrin homology domain of the Saccharomyces cerevisiae OSH1 gene (SGD:S000000081). This domain binds to phosphatidylinositol 4-phosphate and phosphatidylinositol 4,5-bisphosphate with similar affinities, with with a 3-fold lower affinity than Tag:PH(yOSH2) (PMID:15023338). This domain can thus be used to monitor the distribution of phosphatidylinositol 4-phosphate and phosphatidylinositol 4,5-bisphosphate within a cell, if fused to an appropriate reporter protein, or to target a tagged protein to a particular subcellular localization via phosphatidylinositol phosphate binding.