biostudies-literatureKumar GANational Center of Science, PolandSERB Distinguished Fellowship grantInstituto de Salud Carlos III FEDERCouncil of Scientific and Industrial ResearchERA-NET NEURON and Ministry of Economy, Industry and Competitivenesseabh2922https://www.ebi.ac.uk/biostudies/studies/S-EPMC8302130biostudies-literatureUnknown7(30)The function of several G protein-coupled receptors (GPCRs) exhibits cholesterol sensitivity. Cholesterol sensitivity of GPCRs could be attributed to specific sequence and structural features, such as the cholesterol recognition/interaction amino acid consensus (CRAC) motif, that facilitate their cholesterol-receptor interaction. In this work, we explored the molecular basis of cholesterol sensitivity exhibited by the serotonin1A receptor, the most studied GPCR in the context of cholesterol sensitivity, by generating mutants of key residues in CRAC motifs in transmembrane helix 2 (TM2) and TM5 of the receptor. Our results show that a lysine residue (K101) in one of the CRAC motifs is crucial for sensing altered membrane cholesterol levels. Insights from all-atom molecular dynamics simulatiScience advancesA molecular sensor for cholesterol in the human serotonin1A receptor.PMC8302130Core SupportAC18/000302017/27/N/NZ2/02571PI15/00460 and PI18/00094Sarkar PSingh SPStepniewski TMKumar GAJafurulla MSelent JChattopadhyay AfalseA molecular sensor for cholesterol in the human serotonin1A receptor.The function of several G protein-coupled receptors (GPCRs) exhibits cholesterol sensitivity. Cholesterol sensitivity of GPCRs could be attributed to specific sequence and structural features, such as the cholesterol recognition/interaction amino acid consensus (CRAC) motif, that facilitate their cholesterol-receptor interaction. In this work, we explored the molecular basis of cholesterol sensitivity exhibited by the serotonin1A receptor, the most studied GPCR in the context of cholesterol sensitivity, by generating mutants of key residues in CRAC motifs in transmembrane helix 2 (TM2) and TM5 of the receptor. Our results show that a lysine residue (K101) in one of the CRAC motifs is crucial for sensing altered membrane cholesterol levels. Insights from all-atom molecular dynamics simulati2021-01-01T00:00:00Z2021 Jul2025-05-29T20:28:26.345Z2022-02-11T05:37:53.598ZS-EPMC83021303430160610.1126/sciadv.abh2922