Involved in the formation of nucleus-vacuole (NV) junctions during piecemeal microautophagy of the nucleus (PMN). NV junctions are interorganelle interfaces mediated by NVJ1 in the nuclear envelope and VAC8 on the vacuole membrane. Together, NVJ1 and VAC8 form Velcro-like patches through which teardrop-like portions of the nucleus are pinched off into the vacuolar lumen and degraded by the PMN process. Acts also as an outer-nuclear membrane receptor for OSH1 and TSC13 (By similarity). Interacts with OSH1, TSC13 and VAC8.