Abstract. Hydroxycarboxylic acid receptors are class A G-protein-coupled receptors that act as metabolic sensors linking cellular metabolic status to physi

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Plasmid pAAV-CAG-DIO-HA-HCARD-P2A-mCitrine from Dr. Bryan Roth's lab contains the insert hydroxycarboxylic acid receptor 2 and is published in Cell, 2024 This plasmid is available through Addgene.

Abstract. Hydroxycarboxylic acid receptors are class A G-protein-coupled receptors that act as metabolic sensors linking cellular metabolic status to physi

Abstract. Hydroxycarboxylic acid receptors are class A G-protein-coupled receptors that act as metabolic sensors linking cellular metabolic status to physi

Lactic acid (CH3CH(OH)COOH)–a key biorelevant hydroxycarboxylic acid–is ubiquitous in living organisms and critically linked to the molecular origins of life due to its fundamental role in metabolic p...

by Xin Pan, Fang Ye, Peiruo Ning, Yiping Yu, Zhiyi Zhang, Jingxuan Wang, Geng Chen, Zhangsong Wu, Chen Qiu, Jiancheng Li, Bangning Chen, Lizhe Zhu, Chungen Qian, Kaizheng Gong, Yang Du Hydroxycarboxylic acid receptor 1 (HCAR1), also known as lactate receptor or GPR81, is a class A G-protein-coupled receptor with key roles in regulating lipid metabolism, neuroprotection, angiogenesis, cardiovascular function, and inflammatory response in humans. HCAR1 is highly expressed in numerous types of cancer cells, where it participates in controlling cancer cell metabolism and defense mechanisms, rendering it an appealing target for cancer therapy. However, the molecular basis of HCAR1-mediated signaling remains poorly understood. Here, we report four cryo-EM structures of human HCAR1 and HCAR2 in complex with the Gi1 protein, in which HCAR1 binds to the subtype-specific agonist CHBA (3.16 Å) and apo form (3.36 Å), and HCAR2 binds to the subtype-specific agonists MK-1903 (2.68 Å) and SCH900271 (3.06 Å). Combined with mutagenesis and cellular functional assays, we elucidate the mechanisms underlying ligand recognition, receptor activation, and G protein coupling of HCAR1. More importantly, the key residues that determine ligand selectivity between HCAR1 and HCAR2 are clarified. On this basis, we further summarize the structural features of agonists that match the orthosteric pockets of HCAR1 and HCAR2. These structural insights are anticipated to greatly accelerate the development of novel HCAR1-targeted drugs, offering a promising avenue for the treatment of various diseases.

Physical exercise influences hippocampal function and behavior, and lactate has emerged as a candidate signaling molecule linking metabolic activity to neuroplasticity. One proposed mediator is the hydroxycarboxylic acid receptor 1 (HCAR1), but its contribution to behavioral and hippocampal adaptations to exercise remains unclear. We combined studies of HCAR1 knock-out (KO) mice with analyses of human postmortem hippocampal tissue to assess whether HCAR1 is required for behavioral or synaptic responses to exercise and to characterize its spatial distribution in the human hippocampus. Wild-type and HCAR1 KO mice of either sex underwent a 3 week high-intensity interval treadmill program or sedentary handling. Behavioral responses were assessed using the splash test and three-chamber sociability assay, and dentate gyrus (DG) field recordings evaluated synaptic transmission and excitability. In parallel, HCAR1 expression was quantified in the hippocampal tissue from individuals with major depressive disorder (MDD) and nondepressed controls. Exercise reduced grooming and increased locomotion similarly across genotypes, indicating largely preserved behavioral responses in the absence of HCAR1. HCAR1 KO control mice exhibited delayed initiation of social interaction, not observed in exercised mice. Electrophysiology revealed subtle genotype-dependent differences in DG responsiveness following exercise, without major changes in short-term plasticity. In the small available cohort, HCAR1 showed a predominantly perivascular distribution across hippocampal subregions in both MDD and control cases. Together, these findings indicate that HCAR1 is not required for the primary behavioral and synaptic outcomes measured here following exercise, while leaving open a contribution to more specific aspects of hippocampal function under these or other conditions.

Signal Transduction and Targeted Therapy - Orthosteric ligand selectivity and allosteric probe dependence at Hydroxycarboxylic acid receptor HCAR2

Hydroxy-carboxylic acid receptor (HCA) is an attractive drug target for neuroinflammation. Here, authors report cryo-EM structures of the HCA2 and HCA3-Gi complexes with multiple ligands, to describe ...

by Fang Ye, Zhiyi Zhang, Binghao Zhang, Xinyu Li, Jiaxi Deng, Qian Miao, Peiruo Ning, Yunlin Chi, Geng Chen, Zhangsong Wu, Qian Wang, Lezhi Xu, Ningjie Gong, Bangning Cheng, Zhigang Ma, Chungen Qian, Lizhe Zhu, Xin Pan, Yang Du The hydroxycarboxylic acid receptors (HCAR2 and HCAR3), also known as prototypical metabolite-sensing receptors, are key targets for treating dyslipidemia and metabolic disorders. While HCAR2 activation, but not HCAR3 activation, is associated with side effects of cutaneous flushing, the structural features and ligand preferences of HCAR3 remain less understood. Here, we used Sf9 cells to express HCAR3-Gi and HCAR2-Gi complexes, and present cryo-EM structures of HCAR3-Gi complexes with agonists compound 6O (3.31 Å), D-phenyllactic acid (3.05 Å), IBC293 (3.26 Å), and acifran (3.18Å), as well as HCAR2-Gi complex with agonist acifran (2.72 Å). Our findings reveal the mechanism behind 6O’s highest affinity to HCAR3, attributed to its full occupation of both R1 and R2 regions of the orthosteric binding pocket. Moreover, combined with cAMP assay in HEK-293 cells, we have elucidated that the ligand selectivity between HCAR3 and HCAR2 depended on π–π interaction with F1073.32 (L1073.32 in HCAR2) and ligand-binding pocket size difference, facilitated by key residues difference V/L832.60, Y/N862.63, and S/W9123.48. Collectively, these structural insights lay the groundwork for developing HCAR3-specific drugs, potentially avoiding HCAR2-induced adverse effects.

by Fang Ye, Zhiyi Zhang, Binghao Zhang, Xinyu Li, Jiaxi Deng, Qian Miao, Peiruo Ning, Yunlin Chi, Geng Chen, Zhangsong Wu, Qian Wang, Lezhi Xu, Ningjie Gong, Bangning Cheng, Zhigang Ma, Chungen Qian, Lizhe Zhu, Xin Pan, Yang Du The hydroxycarboxylic acid receptors (HCAR2 and HCAR3), also known as prototypical metabolite-sensing receptors, are key targets for treating dyslipidemia and metabolic disorders. While HCAR2 activation, but not HCAR3 activation, is associated with side effects of cutaneous flushing, the structural features and ligand preferences of HCAR3 remain less understood. Here, we used Sf9 cells to express HCAR3-Gi and HCAR2-Gi complexes, and present cryo-EM structures of HCAR3-Gi complexes with agonists compound 6O (3.31 Å), D-phenyllactic acid (3.05 Å), IBC293 (3.26 Å), and acifran (3.18Å), as well as HCAR2-Gi complex with agonist acifran (2.72 Å). Our findings reveal the mechanism behind 6O’s highest affinity to HCAR3, attributed to its full occupation of both R1 and R2 regions of the orthosteric binding pocket. Moreover, combined with cAMP assay in HEK-293 cells, we have elucidated that the ligand selectivity between HCAR3 and HCAR2 depended on π–π interaction with F1073.32 (L1073.32 in HCAR2) and ligand-binding pocket size difference, facilitated by key residues difference V/L832.60, Y/N862.63, and S/W9123.48. Collectively, these structural insights lay the groundwork for developing HCAR3-specific drugs, potentially avoiding HCAR2-induced adverse effects.

by Fang Ye, Zhiyi Zhang, Binghao Zhang, Xinyu Li, Jiaxi Deng, Qian Miao, Peiruo Ning, Yunlin Chi, Geng Chen, Zhangsong Wu, Qian Wang, Lezhi Xu, Ningjie Gong, Bangning Cheng, Zhigang Ma, Chungen Qian, Lizhe Zhu, Xin Pan, Yang Du The hydroxycarboxylic acid receptors (HCAR2 and HCAR3), also known as prototypical metabolite-sensing receptors, are key targets for treating dyslipidemia and metabolic disorders. While HCAR2 activation, but not HCAR3 activation, is associated with side effects of cutaneous flushing, the structural features and ligand preferences of HCAR3 remain less understood. Here, we used Sf9 cells to express HCAR3-Gi and HCAR2-Gi complexes, and present cryo-EM structures of HCAR3-Gi complexes with agonists compound 6O (3.31 Å), D-phenyllactic acid (3.05 Å), IBC293 (3.26 Å), and acifran (3.18Å), as well as HCAR2-Gi complex with agonist acifran (2.72 Å). Our findings reveal the mechanism behind 6O’s highest affinity to HCAR3, attributed to its full occupation of both R1 and R2 regions of the orthosteric binding pocket. Moreover, combined with cAMP assay in HEK-293 cells, we have elucidated that the ligand selectivity between HCAR3 and HCAR2 depended on π–π interaction with F1073.32 (L1073.32 in HCAR2) and ligand-binding pocket size difference, facilitated by key residues difference V/L832.60, Y/N862.63, and S/W9123.48. Collectively, these structural insights lay the groundwork for developing HCAR3-specific drugs, potentially avoiding HCAR2-induced adverse effects.

by Xin Pan, Fang Ye, Peiruo Ning, Yiping Yu, Zhiyi Zhang, Jingxuan Wang, Geng Chen, Zhangsong Wu, Chen Qiu, Jiancheng Li, Bangning Chen, Lizhe Zhu, Chungen Qian, Kaizheng Gong, Yang Du Hydroxycarboxylic acid receptor 1 (HCAR1), also known as lactate receptor or GPR81, is a class A G-protein-coupled receptor with key roles in regulating lipid metabolism, neuroprotection, angiogenesis, cardiovascular function, and inflammatory response in humans. HCAR1 is highly expressed in numerous types of cancer cells, where it participates in controlling cancer cell metabolism and defense mechanisms, rendering it an appealing target for cancer therapy. However, the molecular basis of HCAR1-mediated signaling remains poorly understood. Here, we report four cryo-EM structures of human HCAR1 and HCAR2 in complex with the Gi1 protein, in which HCAR1 binds to the subtype-specific agonist CHBA (3.16 Å) and apo form (3.36 Å), and HCAR2 binds to the subtype-specific agonists MK-1903 (2.68 Å) and SCH900271 (3.06 Å). Combined with mutagenesis and cellular functional assays, we elucidate the mechanisms underlying ligand recognition, receptor activation, and G protein coupling of HCAR1. More importantly, the key residues that determine ligand selectivity between HCAR1 and HCAR2 are clarified. On this basis, we further summarize the structural features of agonists that match the orthosteric pockets of HCAR1 and HCAR2. These structural insights are anticipated to greatly accelerate the development of novel HCAR1-targeted drugs, offering a promising avenue for the treatment of various diseases.

by Xin Pan, Fang Ye, Peiruo Ning, Yiping Yu, Zhiyi Zhang, Jingxuan Wang, Geng Chen, Zhangsong Wu, Chen Qiu, Jiancheng Li, Bangning Chen, Lizhe Zhu, Chungen Qian, Kaizheng Gong, Yang Du Hydroxycarboxylic acid receptor 1 (HCAR1), also known as lactate receptor or GPR81, is a class A G-protein-coupled receptor with key roles in regulating lipid metabolism, neuroprotection, angiogenesis, cardiovascular function, and inflammatory response in humans. HCAR1 is highly expressed in numerous types of cancer cells, where it participates in controlling cancer cell metabolism and defense mechanisms, rendering it an appealing target for cancer therapy. However, the molecular basis of HCAR1-mediated signaling remains poorly understood. Here, we report four cryo-EM structures of human HCAR1 and HCAR2 in complex with the Gi1 protein, in which HCAR1 binds to the subtype-specific agonist CHBA (3.16 Å) and apo form (3.36 Å), and HCAR2 binds to the subtype-specific agonists MK-1903 (2.68 Å) and SCH900271 (3.06 Å). Combined with mutagenesis and cellular functional assays, we elucidate the mechanisms underlying ligand recognition, receptor activation, and G protein coupling of HCAR1. More importantly, the key residues that determine ligand selectivity between HCAR1 and HCAR2 are clarified. On this basis, we further summarize the structural features of agonists that match the orthosteric pockets of HCAR1 and HCAR2. These structural insights are anticipated to greatly accelerate the development of novel HCAR1-targeted drugs, offering a promising avenue for the treatment of various diseases.

Author summary Although it has been known for 15 years th...

In an equilibrium dialysis assay (bismuth being determined by atomic absorption spectrometry) a constant amount of bismuth (Bi. CAS 7440-69-9) (final maximum conc. 50 mu-mol Bi/l) was dialyzed against solutions with increasing concentration...