Scaffold protein component of the PI(3,5)P2 regulatory complex which regulates both the synthesis and turnover of phosphatidylinositol 3,5-bisphosphate (PtdIns(3,5)P2). Pentamerizes into a star-shaped structure and nucleates the assembly of the complex. The pentamer binds a single copy each of PIKFYVE and FIG4 and coordinates both PIKfyve kinase activity and FIG4 phosphatase activity, being required to maintain normal levels of phosphatidylinositol 3-phosphate (PtdIns(3)P) and phosphatidylinositol 5-phosphate (PtdIns(5)P). Plays a role in the biogenesis of endosome carrier vesicles (ECV) / multivesicular bodies (MVB) transport intermediates from early endosomes. Forms pentamers. Component of the PI(3,5)P2 regulatory complex/PAS complex, at least composed of PIKFYVE, FIG4 and VAC14. VAC14 nucleates the assembly of the complex and serves as a scaffold by pentamerizing into a star-shaped structure, which can bind a single copy each of PIKFYVE and FIG4 and coordinates their activities. Interacts with NOS1. Mainly associated with membranes of the late endocytic pathway. Ubiquitous. The C-terminal domain (residues 523-782) mediates pentameric interactions and is necessary for the formation and maintenance of the PI(3,5)P2 regulatory complex. Defects in Vac14 are the cause of the infantile gliosis phenotype (ingls). Mice exhibit reduced body size and diluted pigmentation that can be recognized as early as postnatal day 3 (P3). By P14, the mice exhibit a tremor and impaired motor function. Maximal survival of the mice is for 3 weeks. Small areas with the appearance of spongiform degeneration are visible in several brain regions, including the thalamus, brain stem and cerebellar nucleus. Mice die perinatally and exhibit profound degeneration in certain regions of the central and peripheral nervous systems. Selected regions in the brain are affected, especially the medulla, the pons and the midbrain and increased cell death occurs in these areas. Affected neurons contain large vacuoles. Belongs to the VAC14 family.