Participates in the organization of endoplasmic reticulum- plasma membrane contact sites (EPCS) with pleiotropic functions including STIM1 recruitment and calcium homeostasis. Constitutive tether that co-localize with ESYT2/3 tethers at endoplasmic reticulum- plasma membrane contact sites in a phosphatidylinositol lipid-dependent manner. Pre-marks the subset of phosphtidylinositol 4,5-biphosphate (PI(4,5)P2)-enriched EPCS destined for the store operated calcium entry pathway (SOCE). . This is the function of ENSG00000175318 (GRAMD2A, GRAM domain containing 2A).