Selenoprotein with thioredoxin reductase-like oxidoreductase activity (By similarity). Protects dopaminergic neurons against oxidative stress and cell death (PubMed:26866473). Involved in ADCYAP1/PACAP-induced calcium mobilization and neuroendocrine secretion (By similarity). Plays a role in fibroblast anchorage and redox regulation (By similarity). In gastric smooth muscle, modulates the contraction processes through the regulation of calcium release and MYLK activation (By similarity). In pancreatic islets, involved in the control of glucose homeostasis, contributes to prolonged ADCYAP1/PACAP- induced insulin secretion (By similarity). {ECO:0000250|UniProtKB:P62342, ECO:0000250|UniProtKB:Q1H5H1, ECO:0000269|PubMed:26866473}. This is the function of ENSG00000198843 (SELENOT, selenoprotein T).