Involved in regulation of various organellar membrane contact sites (PubMed:26119743). May be involved in sterol transfer between intracellular membranes (PubMed:26001273). Selectively transports sterols between membranes in vitro. Involved in stress-dependent formation of sterol-enriched vacuolar membrane domains (PubMed:25987606). Interacts with the ERMES complex. Localizes to intracellular puncta representing endoplasmic reticulum-mitochondrion membrane contact sites (ERMES), nucleus-vacuole junctions (NVJ) and vacuole-mitochondria patches (vCLAMP) (PubMed:14562095, PubMed:26119743, PubMed:26001273, PubMed:25987606). Localization to ER-mitochondria contacts is dependent on TOM70/TOM71, and localization to ER-vacuole junctions on VAC8 (PubMed:25987606). The VASt domain bind sterols. Belongs to the YSP2 family.