This entry represents a domain found in 36 kDa major membrane protein F5 and Telomere-binding protein I6 from Vaccinia virus, and similar sequences from poxvirus. F5, also named Protein OPG049, plays a role in the spread of virus to neighbouring cells ex vivo []. I6, also known as Telomere-binding protein OPG082, binds tightly and with great specificity to the hairpin form of the viral telomeric sequence. This telomere binding protein is thought to play a role in the initiation of vaccinia virus genome replication and/or genome encapsidation [, ].
This domain is found at the N-terminal end of Homo sapiens adhesion G-protein-coupled receptor F3 and F5 (ADGRF3/F5), orphan receptors. This domain is predicted to have an ��-�� configuration.In homo sapiens, ADGRF3 is a receptor for soluble FNDC4 (sFNDC4), required for proper systemic glucose tolerance, specifically sensitising white adipose tissue to insulin [].The adhesion GPCR (aGPCR) family plays critical physiological functions in the human immune system, central nervous system, cellular communication, reproduction, organ development, homeostasis, and other processes []As the second largest group in the GPCR superfamily, aGPCRs are differentiated from other GPCRs by a large extracellular region (ECD) that contains a tandem adhesion domain, followed by the SEA domain , a conserved GPCR autoproteolysis-inducing (GAIN) domain (GAIN A and GAIN B ) juxtaposed to a canonical seven-transmembrane domain (7TM) (). Most aGPCRs are orphan receptors with few known ligand associations identified. The synthesised Stachel peptide is capable of activating aGPCRs, suggesting that the Stachel peptide plays a critical role in aGPCR activation.
