Fig. 3.

Schematic diagram of GPCR signaling pathways activated by HCMV US28 receptor without any ligand binding. Agonist-independent signaling pathways by US28 were drawn based on specific functions of two different members of activated Gα and Gβγ complex without ligand binding. Major effector proteins mediating downstream signaling and activated transcription factors were also depicted. Acronyms used are as follows. AC: adenylyl cyclase, PKA: protein kinase A, SERCA: sarcoplasmic reticulum calcium ATPase, NFAT: nuclear factor of activated T-cells, NF-κB: nuclear factor kappa-light-chain-enhancer of activated B cells, IL-6: interleukin 6, JAK1: Janus kinase 1, STAT3: signal transducer and activator of transcription 3, COX: cyclic oxygenase, VEGF: vascular epidermal growth factor, DRY: dry motif. VUF2274 is an inverse agonist for US28.