Unraveling the Molecular Nexus between GPCRs, ERS, and EMT

Figure 1

G protein-coupled receptor (GPCR) signaling pathway. Human GPCRs are seven-transmembrane receptor proteins divided into six classes (A, B1, B2, C, F, and Taste2). They receive signals from various stimuli (hormones, growth factors, neurotransmitters, etc.) and transduce the signal through G proteins in the cytosol. G proteins are made up of three subunits (α, β, and γ) and are anchored in the plasma membrane by binding through the α and γ subunits, while GPCRs bind G proteins through the α subunit. In the absence of stimuli, the Gα subunit binds ADP and is inactive. However, upon activation, the α subunit binds ATP and dissociates from the β and γ subunits. There are four different types of Gα subunits (Gαs, Gαi/o, Gαq/11, and Gα12/13), which further relay the signal to downstream targets, ultimately leading to gene transcription. The dissociated Gβ-Gγ dimer also participates in various downstream signaling pathways. In cancer, GPCR signaling is altered, leading to the activation of genes involved in cancer cell survival and progression.