1
|
Ponnusamy V, Subramanian G, Muthuswamy K, Shanmugamprema D, Krishnan V, Velusamy T, Subramaniam S. Genetic variation in sweet taste receptors and a mechanistic perspective on sweet and fat taste sensation in the context of obesity. Obes Rev 2022; 23:e13512. [PMID: 36282093 DOI: 10.1111/obr.13512] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Revised: 09/14/2022] [Accepted: 10/05/2022] [Indexed: 11/30/2022]
Abstract
Taste sensation enables humans to make nutritionally important decisions such as food preference and consumption. It functions as deterministic factors for unpropitious eating behavior, leading to overweight and obesity. The hedonistic feeling on consumption of fat and sugar-rich meals, in particular, has a negative influence on health. In addition, impairment in the taste receptors alters the downstream signaling of taste transduction pathway. Hence, genetic polymorphism in typical taste receptors is a predictor of taste sensitivity variance across individuals. The present review summarizes the effect of a single nucleotide polymorphism (SNP) in sweet taste receptors (T1R2/T1R3) on taste perception among individuals of various body mass index (BMI). Furthermore, in the context of obesity, we discussed the possibility of crosstalk between fat and sweet receptors as well as taste dysfunction in diseased individuals. In overall, a greater understanding of the physiological relationship between taste receptors, altered taste sensitivity, and genetic polymorphisms should lead to more effective obesity prevention approaches.
Collapse
Affiliation(s)
- Vinithra Ponnusamy
- Molecular Physiology Laboratory, Department of Biochemistry, Bharathiar University, Coimbatore, Tamilnadu, India, 641046
| | - Gowtham Subramanian
- Molecular Physiology Laboratory, Department of Biochemistry, Bharathiar University, Coimbatore, Tamilnadu, India, 641046
| | - Karthi Muthuswamy
- Molecular Physiology Laboratory, Department of Biochemistry, Bharathiar University, Coimbatore, Tamilnadu, India, 641046
| | - Deepankumar Shanmugamprema
- Molecular Physiology Laboratory, Department of Biochemistry, Bharathiar University, Coimbatore, Tamilnadu, India, 641046
| | - Vasanth Krishnan
- Molecular Biology Laboratory, Department of Botany, School of Life Sciences, Bharathiar University, Coimbatore, Tamilnadu, India, 641046
| | - Thirunavukkarasu Velusamy
- Department of Biotechnology, School of Biotechnology and Genetic Engineering, Bharathiar University, Coimbatore, Tamilnadu, India, 641046
| | - Selvakumar Subramaniam
- Molecular Physiology Laboratory, Department of Biochemistry, Bharathiar University, Coimbatore, Tamilnadu, India, 641046
| |
Collapse
|
2
|
Okubo S, Terauchi K, Okada S, Saito Y, Yamaura T, Misaka T, Nakajima KI, Abe K, Asakura T. De novo transcriptome analysis and comparative expression profiling of genes associated with the taste-modifying protein neoculin in Curculigo latifolia and Curculigo capitulata fruits. BMC Genomics 2021; 22:347. [PMID: 33985426 PMCID: PMC8120819 DOI: 10.1186/s12864-021-07674-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Accepted: 05/05/2021] [Indexed: 11/29/2022] Open
Abstract
Background Curculigo latifolia is a perennial plant endogenous to Southeast Asia whose fruits contain the taste-modifying protein neoculin, which binds to sweet receptors and makes sour fruits taste sweet. Although similar to snowdrop (Galanthus nivalis) agglutinin (GNA), which contains mannose-binding sites in its sequence and 3D structure, neoculin lacks such sites and has no lectin activity. Whether the fruits of C. latifolia and other Curculigo plants contain neoculin and/or GNA family members was unclear. Results Through de novo RNA-seq assembly of the fruits of C. latifolia and the related C. capitulata and detailed analysis of the expression patterns of neoculin and neoculin-like genes in both species, we assembled 85,697 transcripts from C. latifolia and 76,775 from C. capitulata using Trinity and annotated them using public databases. We identified 70,371 unigenes in C. latifolia and 63,704 in C. capitulata. In total, 38.6% of unigenes from C. latifolia and 42.6% from C. capitulata shared high similarity between the two species. We identified ten neoculin-related transcripts in C. latifolia and 15 in C. capitulata, encoding both the basic and acidic subunits of neoculin in both plants. We aligned these 25 transcripts and generated a phylogenetic tree. Many orthologs in the two species shared high similarity, despite the low number of common genes, suggesting that these genes likely existed before the two species diverged. The relative expression levels of these genes differed considerably between the two species: the transcripts per million (TPM) values of neoculin genes were 60 times higher in C. latifolia than in C. capitulata, whereas those of GNA family members were 15,000 times lower in C. latifolia than in C. capitulata. Conclusions The genetic diversity of neoculin-related genes strongly suggests that neoculin genes underwent duplication during evolution. The marked differences in their expression profiles between C. latifolia and C. capitulata may be due to mutations in regions involved in transcriptional regulation. Comprehensive analysis of the genes expressed in the fruits of these two Curculigo species helped elucidate the origin of neoculin at the molecular level. Supplementary Information The online version contains supplementary material available at 10.1186/s12864-021-07674-3.
Collapse
Affiliation(s)
- Satoshi Okubo
- The Yamashina Botanical Research Institute, Nippon Shinyaku Co., Ltd., Oyake Sakanotsuji-cho 39, Yamashina-ku, Kyoto, 607-8182, Japan
| | - Kaede Terauchi
- Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1, Yayoi, Bunkyo-ku, Tokyo, 113-8657, Japan
| | - Shinji Okada
- Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1, Yayoi, Bunkyo-ku, Tokyo, 113-8657, Japan
| | - Yoshikazu Saito
- Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1, Yayoi, Bunkyo-ku, Tokyo, 113-8657, Japan
| | - Takao Yamaura
- The Yamashina Botanical Research Institute, Nippon Shinyaku Co., Ltd., Oyake Sakanotsuji-cho 39, Yamashina-ku, Kyoto, 607-8182, Japan
| | - Takumi Misaka
- Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1, Yayoi, Bunkyo-ku, Tokyo, 113-8657, Japan
| | - Ken-Ichiro Nakajima
- Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1, Yayoi, Bunkyo-ku, Tokyo, 113-8657, Japan.,Present address: Division of Endocrinology and Metabolism, National Institute for Physiological Sciences, 38 Nishigonaka, Myodaiji, Okazaki, Aichi, 444-8585, Japan
| | - Keiko Abe
- Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1, Yayoi, Bunkyo-ku, Tokyo, 113-8657, Japan.,Kanagawa Institute of Industrial Science and Technology (KISTEC), 3-25-13 Tonomachi, Kawasaki-ku, Kawasaki, Kanagawa, 210-0821, Japan
| | - Tomiko Asakura
- Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1, Yayoi, Bunkyo-ku, Tokyo, 113-8657, Japan.
| |
Collapse
|
3
|
Abstract
AbstractA major challenge in taste research is to overcome the flavour imperfections in food products and to build nutritious strategies to combat against obesity as well as other related metabolic syndromes. The field of molecular taste research and chemical senses has contributed to an enormous development in understanding the taste receptors and mechanisms of taste perception. Accordingly, the development of taste-modifying compounds or taste modulators that alter the perception of basic taste modalities has gained significant prominence in the recent past. The beneficial aspects of these substances are overwhelming while considering their potential taste-modifying properties. The objective of the present review is to provide an impression about the taste-modulating compounds and their distinctive taste-modifying properties with reference to their targets and proposed mechanisms of action. The present review also makes an effort to discuss the basic mechanism involved in oro-gustatory taste perception as well as on the effector molecules involved in signal transduction downstream to the activation of taste receptors.
Collapse
|
4
|
Park J, Selvam B, Sanematsu K, Shigemura N, Shukla D, Procko E. Structural architecture of a dimeric class C GPCR based on co-trafficking of sweet taste receptor subunits. J Biol Chem 2019; 294:4759-4774. [PMID: 30723160 DOI: 10.1074/jbc.ra118.006173] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2018] [Revised: 01/24/2019] [Indexed: 01/06/2023] Open
Abstract
Class C G protein-coupled receptors (GPCRs) are obligatory dimers that are particularly important for neuronal responses to endogenous and environmental stimuli. Ligand recognition through large extracellular domains leads to the reorganization of transmembrane regions to activate G protein signaling. Although structures of individual domains are known, the complete architecture of a class C GPCR and the mechanism of interdomain coupling during receptor activation are unclear. By screening a mutagenesis library of the human class C sweet taste receptor subunit T1R2, we enhanced surface expression and identified a dibasic intracellular retention motif that modulates surface expression and co-trafficking with its heterodimeric partner T1R3. Using a highly expressed T1R2 variant, dimerization sites along the entire subunit within all the structural domains were identified by a comprehensive mutational scan for co-trafficking with T1R3 in human cells. The data further reveal that the C terminus of the extracellular cysteine-rich domain needs to be properly folded for T1R3 dimerization and co-trafficking, but not for surface expression of T1R2 alone. These results guided the modeling of the T1R2-T1R3 dimer in living cells, which predicts a twisted arrangement of domains around the central axis, and a continuous folded structure between transmembrane domain loops and the cysteine-rich domains. These insights have implications for how conformational changes between domains are coupled within class C GPCRs.
Collapse
Affiliation(s)
- Jihye Park
- From the Departments of Biochemistry and
| | - Balaji Selvam
- Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801 and
| | - Keisuke Sanematsu
- the Section of Oral Neuroscience, Graduate School of Dental Science, and.,the Division of Sensory Physiology-Medical Application Sensing, Research and Development Center for Five-Sense Devices, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan
| | - Noriatsu Shigemura
- the Section of Oral Neuroscience, Graduate School of Dental Science, and.,the Division of Sensory Physiology-Medical Application Sensing, Research and Development Center for Five-Sense Devices, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan
| | - Diwakar Shukla
- Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801 and
| | | |
Collapse
|
5
|
Masuda T, Kigo S, Mitsumoto M, Ohta K, Suzuki M, Mikami B, Kitabatake N, Tani F. Positive Charges on the Surface of Thaumatin Are Crucial for the Multi-Point Interaction with the Sweet Receptor. Front Mol Biosci 2018; 5:10. [PMID: 29487853 PMCID: PMC5816810 DOI: 10.3389/fmolb.2018.00010] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2017] [Accepted: 01/24/2018] [Indexed: 11/21/2022] Open
Abstract
Thaumatin, an intensely sweet-tasting protein, elicits sweet taste with a threshold of only 50 nM. Previous studies from our laboratory suggested that the complex model between the T1R2-T1R3 sweet receptor and thaumatin depends critically on the complementarity of electrostatic potentials. In order to further validate this model, we focused on three lysine residues (Lys78, Lys106, and Lys137), which were expected to be part of the interaction sites. Three thaumatin mutants (K78A, K106A, and K137A) were prepared and their threshold values of sweetness were examined. The results showed that the sweetness of K106A was reduced by about three times and those of K78A and K137A were reduced by about five times when compared to wild-type thaumatin. The three-dimensional structures of these mutants were also determined by X-ray crystallographic analyses at atomic resolutions. The overall structures of mutant proteins were similar to that of wild-type but the electrostatic potentials around the mutated sites became more negative. Since the three lysine residues are located in 20-40 Å apart each other on the surface of thaumatin molecule, these results suggest the positive charges on the surface of thaumatin play a crucial role in the interaction with the sweet receptor, and are consistent with a large surface is required for interaction with the sweet receptor, as proposed by the multipoint interaction model named wedge model.
Collapse
Affiliation(s)
- Tetsuya Masuda
- Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Uji, Japan
| | - Satomi Kigo
- Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Uji, Japan
| | - Mayuko Mitsumoto
- Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Uji, Japan
| | - Keisuke Ohta
- Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Uji, Japan
| | - Mamoru Suzuki
- Laboratory of Supramolecular Crystallography, Research Center for State-of-the-Art Functional Protein Analysis, Institute for Protein Research, Osaka University, Suita, Japan
| | - Bunzo Mikami
- Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Uji, Japan
| | - Naofumi Kitabatake
- Department of Foods and Human Nutrition, Notre Dame Seishin University, Okayama, Japan
| | - Fumito Tani
- Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Uji, Japan
| |
Collapse
|