Adaptive evolution plays a role in the functional divergence and specialization of taste receptors and the sense of taste is thought to be closely related to feeding ecology.To examine whether feeding ecology has shap...Adaptive evolution plays a role in the functional divergence and specialization of taste receptors and the sense of taste is thought to be closely related to feeding ecology.To examine whether feeding ecology has shaped the evolution of taste receptor genes in vertebrates,we here focus on Tas1r gene family that encodes umami(Tas1r1 and Tas1r3 heterodimer) and sweet(Tas1r2 and Tas1r3 heterodimer) taste receptors.By searching currently available genome sequences in 48 vertebrates that contain 38 mammals,1 reptile,3 birds,1 frog,and 5 fishes,we found all three members of Tas1rs are intact in most species,suggesting umami and sweet tastes are maintained in most vertebrates.Interestingly,the absence and pseudogenization of Tas1rs were also discovered in a number of species with diverse feeding preferences and distinct phylogenetic positions,indicating widespread losses of umami and/or sweet tastes in these animals,irrespective of their diet.Together with previous findings showing losses of tastes in other vertebrates,we failed to identify common dietary factors that could result in the taste losses.Our results report here suggest the evolution of Tas1rs is more complex than we previously appreciated and highlight the caveat of analyzing sequences predicted from draft genome sequences.Future work for a better understanding of taste receptor function would help uncover what ecological factors have driven the evolution history of Tas1rs in vertebrates.展开更多
Sweet and umami tastes are elicited by sweet and umami receptors on the tongue and palate epithelium,respectively.However,the molecular machinery allowing the taste reaction remains incompletely understood.Through a p...Sweet and umami tastes are elicited by sweet and umami receptors on the tongue and palate epithelium,respectively.However,the molecular machinery allowing the taste reaction remains incompletely understood.Through a phosphoproteomic approach,we identified the key proteins that trigger taste mechanisms based on phosphorylation cascades.Ryanodine receptor isoform 1(RYR1)was further verified by sensory and behavioral assays.We propose a model of RYR1-mediated sweet/umami signaling in which the RYR1 channel,which mediates Ca^(2+)release from the endoplasmic reticulum,is closed by dephosphorylation in bud tissue after sweet/umami treatment.The alteration in Ca^(2+)content in the cytosol induces transient membrane depolarization and generates a cell current for taste signal transduction.We demonstrate that RYR1 is a new channel involved in the regulation of sweet/umami signal transduction and propose a“metabolic clock”notion based on sweet/umami sensing.Our study provides a valuable foundation for a system-level understanding of the taste perception mechanism.展开更多
Like olfaction,the sense of taste allows the detection and discrimination of chemicals in the environment.However,while olfaction is specialized in the detection of volatile chemicals,taste is restricted to the detect...Like olfaction,the sense of taste allows the detection and discrimination of chemicals in the environment.However,while olfaction is specialized in the detection of volatile chemicals,taste is restricted to the detection of contact-chemicals.Two families of mammalian taste receptors,T1R and T2R,involved in recognition of sweet,umami(the taste of monosodium glutamate)and bitter stimuli have been identified and characterized.Although much progress has been made in studies on the basic mechanisms of taste recognition and signal transduction in mammals,we are still far from a full understanding of different taste qualities.This review presents a current perspective on sweet,bitter and umami taste receptors and their signal transduction mechanism.We also discuss the evolution of taste and taste-related molecules.展开更多
Bitter(T2R)and sweet(T1R)taste receptors have been implicated in sinonasal innate immunity and in the pathophysiology of chronic rhinosinusitis(CRS).Taste receptors are expressed on several sinonasal cell types includ...Bitter(T2R)and sweet(T1R)taste receptors have been implicated in sinonasal innate immunity and in the pathophysiology of chronic rhinosinusitis(CRS).Taste receptors are expressed on several sinonasal cell types including ciliated epithelial cells and solitary chemosensory cells.Bitter agonists released by pathogenic microbes elicit a T2R dependent signaling cascade which induces the release of bactericidal nitric oxide,increases mucociliary clearance,and promotes secretion of antimicrobial peptides.Genetic variation conferred by polymorphisms in T2R related genes is associated with differential CRS susceptibility,symptomatology and post-treatment outcomes.More recently,based on our understanding of T1R and T2R function,investigators have discovered novel potential therapeutics in T2R agonists and T1R antagonists.This review will discuss bitter and sweet taste receptor function in sinonasal immunity,explore the emerging diagnostic and therapeutic implications stemming from the most recent findings,and suggest directions for future research.展开更多
基金supported by a start-up fund from Wuhan University to H. Z
文摘Adaptive evolution plays a role in the functional divergence and specialization of taste receptors and the sense of taste is thought to be closely related to feeding ecology.To examine whether feeding ecology has shaped the evolution of taste receptor genes in vertebrates,we here focus on Tas1r gene family that encodes umami(Tas1r1 and Tas1r3 heterodimer) and sweet(Tas1r2 and Tas1r3 heterodimer) taste receptors.By searching currently available genome sequences in 48 vertebrates that contain 38 mammals,1 reptile,3 birds,1 frog,and 5 fishes,we found all three members of Tas1rs are intact in most species,suggesting umami and sweet tastes are maintained in most vertebrates.Interestingly,the absence and pseudogenization of Tas1rs were also discovered in a number of species with diverse feeding preferences and distinct phylogenetic positions,indicating widespread losses of umami and/or sweet tastes in these animals,irrespective of their diet.Together with previous findings showing losses of tastes in other vertebrates,we failed to identify common dietary factors that could result in the taste losses.Our results report here suggest the evolution of Tas1rs is more complex than we previously appreciated and highlight the caveat of analyzing sequences predicted from draft genome sequences.Future work for a better understanding of taste receptor function would help uncover what ecological factors have driven the evolution history of Tas1rs in vertebrates.
基金supported by the National Natural Science Foundation of China(31972198,31622042,31901813,31671857,31901782).
文摘Sweet and umami tastes are elicited by sweet and umami receptors on the tongue and palate epithelium,respectively.However,the molecular machinery allowing the taste reaction remains incompletely understood.Through a phosphoproteomic approach,we identified the key proteins that trigger taste mechanisms based on phosphorylation cascades.Ryanodine receptor isoform 1(RYR1)was further verified by sensory and behavioral assays.We propose a model of RYR1-mediated sweet/umami signaling in which the RYR1 channel,which mediates Ca^(2+)release from the endoplasmic reticulum,is closed by dephosphorylation in bud tissue after sweet/umami treatment.The alteration in Ca^(2+)content in the cytosol induces transient membrane depolarization and generates a cell current for taste signal transduction.We demonstrate that RYR1 is a new channel involved in the regulation of sweet/umami signal transduction and propose a“metabolic clock”notion based on sweet/umami sensing.Our study provides a valuable foundation for a system-level understanding of the taste perception mechanism.
基金the grants of National Natural Science Foundation of China(31572259)the Fundamental Research Funds for the Central Universities of China(201822020,201841013).
文摘Like olfaction,the sense of taste allows the detection and discrimination of chemicals in the environment.However,while olfaction is specialized in the detection of volatile chemicals,taste is restricted to the detection of contact-chemicals.Two families of mammalian taste receptors,T1R and T2R,involved in recognition of sweet,umami(the taste of monosodium glutamate)and bitter stimuli have been identified and characterized.Although much progress has been made in studies on the basic mechanisms of taste recognition and signal transduction in mammals,we are still far from a full understanding of different taste qualities.This review presents a current perspective on sweet,bitter and umami taste receptors and their signal transduction mechanism.We also discuss the evolution of taste and taste-related molecules.
基金This work was supported by the National Institute on Deafness and Other Communication Disorders of the National Institutes of Health under award number R01DC013588-04S2(to IWM).
文摘Bitter(T2R)and sweet(T1R)taste receptors have been implicated in sinonasal innate immunity and in the pathophysiology of chronic rhinosinusitis(CRS).Taste receptors are expressed on several sinonasal cell types including ciliated epithelial cells and solitary chemosensory cells.Bitter agonists released by pathogenic microbes elicit a T2R dependent signaling cascade which induces the release of bactericidal nitric oxide,increases mucociliary clearance,and promotes secretion of antimicrobial peptides.Genetic variation conferred by polymorphisms in T2R related genes is associated with differential CRS susceptibility,symptomatology and post-treatment outcomes.More recently,based on our understanding of T1R and T2R function,investigators have discovered novel potential therapeutics in T2R agonists and T1R antagonists.This review will discuss bitter and sweet taste receptor function in sinonasal immunity,explore the emerging diagnostic and therapeutic implications stemming from the most recent findings,and suggest directions for future research.
