Probable inactive E3 ubiquitin-protein ligase that plays a role in regulation of autophagy. Upon starvation, involved in maintaining ATG6 homeostasis by competitively associating with ATG6, a component of the autophagosome complex (PubMed:28351989). Acts as positive regulator of drought stress response. Functions as positive regulator of abscisic acid-mediated stomatal closure (PubMed:24350984). Homodimer (PubMed:24350984). Interacts with SINAT1, SINAT2, SINAT3, SINAT4 and SINAT5 (PubMed:24350984). Interacts with ATG6 and TRAF1A (PubMed:28351989). Expressed in roots, rosette leaves, cauline leaves, guard cells and flowers. Induced by abscisic acid (ABA) and salt stress. No visible phenotype under normal growth conditions, but mutant plants are hypersensitive to drought stress. Belongs to the SINA (Seven in absentia) family. Lacks the RING-type zinc finger domain that is essential for ubiquitin ligase activity. May not possess E3 ubiquitin-protein ligase activity by itself.