Plays a role as antagonist of host tetherin (BST2), disrupting its antiviral effect. Acts by binding to BST2 and sequestering it to perinuclear region, thereby preventing its antiviral function at cell membrane. Interacts with host BST2 (PubMed:33930332). Interacts with the spike glycoprotein (By similarity). Interacts with M protein (By similarity). Interacts with E protein (By similarity). Interacts with the ORF3a protein (By similarity). The di-lysine motif confers endoplasmic reticulum localization for type I membrane proteins. Poly-ubiquitinated by host with K63-linked polyubiquitin chains. Variant B.1.1.7 is also called Variant Of Concern (VOC) 202012/01, Variant Under Investigation (VUI) 202012/01, or 20B/501Y.V1.