TAS2R38

Summary

TAS2R38 (taste 2 receptor member 38, HGNC:9584) is a protein-coding gene on chromosome 7q34, encoding Taste receptor type 2 member 38 (P59533). Receptor that may play a role in the perception of bitterness and is gustducin-linked.

This gene encodes a seven-transmembrane G protein-coupled receptor that controls the ability to taste glucosinolates, a family of bitter-tasting compounds found in plants of the Brassica sp. Synthetic compounds phenylthiocarbamide (PTC) and 6-n-propylthiouracil (PROP) have been identified as ligands for this receptor and have been used to test the genetic diversity of this gene. Although several allelic forms of this gene have been identified worldwide, there are two predominant common forms (taster and non-taster) found outside of Africa. These alleles differ at three nucleotide positions resulting in amino acid changes in the protein (A49P, A262V, and V296I) with the amino acid combination PAV identifying the taster variant (and AVI identifying the non-taster variant).

Source: NCBI Gene 5726 — RefSeq curated summary.

At a glance

• Gene–disease (curated): thiourea tasting (Limited, GenCC)
• GWAS associations: 7
• Clinical variants (ClinVar): 61 total
• Phenotypes (HPO): 2
• Druggable target: yes — 2 molecules with ChEMBL bioactivity
• MANE Select transcript: NM_176817

Identifiers

Gene identifiers

Field	Value
HGNC ID	HGNC:9584
Approved symbol	TAS2R38
Name	taste 2 receptor member 38
Location	7q34
Locus type	gene with protein product
Status	Approved
Aliases	T2R61
Ensembl gene	ENSG00000257138
Ensembl biotype	protein_coding
OMIM	607751
Entrez	5726

Gene structure

Transcript identifiers

Ensembl transcripts: 1 — 1 protein_coding

ENST00000547270

RefSeq mRNA: 1 — MANE Select: NM_176817 NM_176817

CCDS: CCDS34765

Canonical transcript exons

ENST00000547270 — 1 exons

Exon	Start	End
ENSE00002392323	141972631	141973773

Expression profiles

Bgee: expression breadth broad, 12 present calls, max score 56.49.

Top tissues by expression

236 total, by Bgee expression score (0-100, higher = more expressed):

Tissue	Anatomy ID	Expression score	Quality
epithelium of nasopharynx	UBERON:0001951	56.49	gold quality
oocyte	CL:0000023	55.78	gold quality
sperm	CL:0000019	55.61	gold quality
skin of hip	UBERON:0001554	55.20	silver quality
lower lobe of lung	UBERON:0008949	51.72	silver quality
buccal mucosa cell	CL:0002336	46.14	gold quality
subthalamic nucleus	UBERON:0001906	45.37	gold quality
rectum	UBERON:0001052	45.09	gold quality
vastus lateralis	UBERON:0001379	44.80	gold quality
quadriceps femoris	UBERON:0001377	44.69	gold quality
mucosa of transverse colon	UBERON:0004991	44.21	silver quality
bone marrow cell	CL:0002092	43.44	gold quality
skeletal muscle tissue of rectus abdominis	UBERON:0004511	43.37	gold quality
mucosa of paranasal sinus	UBERON:0005030	42.87	gold quality
secondary oocyte	CL:0000655	42.57	gold quality
mammalian vulva	UBERON:0000997	42.43	gold quality
dorsal plus ventral thalamus	UBERON:0001897	42.39	gold quality
gingival epithelium	UBERON:0001949	42.24	gold quality
heart right ventricle	UBERON:0002080	41.85	gold quality
dorsal root ganglion	UBERON:0000044	41.65	gold quality
sural nerve	UBERON:0015488	41.54	silver quality
trigeminal ganglion	UBERON:0001675	41.47	gold quality
inferior vagus X ganglion	UBERON:0005363	41.40	gold quality
superficial temporal artery	UBERON:0001614	41.33	gold quality
ventral tegmental area	UBERON:0002691	41.18	gold quality
oviduct epithelium	UBERON:0004804	41.11	gold quality
palpebral conjunctiva	UBERON:0001812	41.10	gold quality
gingiva	UBERON:0001828	41.01	gold quality
amniotic fluid	UBERON:0000173	40.69	gold quality
mammary duct	UBERON:0001765	40.65	gold quality

Single-cell (SCXA)

Detected in 1 experiment(s), a significant marker in 0.

Experiment	Marker?	Max mean expression
E-ANND-3	no	1.14

Regulation

Is transcription factor: no

Literature-anchored findings (GeneRIF, showing 40)

• positional cloning of the quantitative trait locus underlying taste sensitivity to phenylthiocarbamide; identified three coding SNPs giving rise to five haplotypes; these haplotypes explain the bimodal distribution of PTC taste sensitivity (PMID:12595690)
• balancing natural selection has acted to maintain “taster” and “nontaster” alleles at the PTC locus in humans (PMID:14997422)
• Activation by 6-nitrosaccharin, a derivative of saccharin. (PMID:15337684)
• The role of the TAS2R38 receptor for taste sensitivity was studied. (PMID:15466815)
• review of the recent discovery of the PTC gene, the developments in taste physiology and population genetics that have followed, and the implications of this work for understanding phenotypic variation in taste perception in general (PMID:15733260)
• models suggest that the inability of humans to taste PTC is due to a failure of G protein activation rather than decreased binding affinity of the receptor for PTC. (PMID:16607493)
• Variation in the TAS2R38 gene alters taste sensitivity. (PMID:16979544)
• Functional variants in both TAS2R16 and TAS2R38 correlate with alcohol consumption in African-American families. (PMID:17250611)
• TAS2R38 variation may also be associated with intermediate tasting ability (PMID:17662150)
• Propylthiouracil bitterness predicts heightened intensity across taste qualities (supertasting) even after controlling for TAS2R38 variation, indicating TAS2R38 cannot explain supertasting. Threshold and suprathreshold intensity are distinct phenotypes. (PMID:18209019)
• TAS2R38 polymorphisms were insufficient to explain suprathreshold bitterness elicied by concentrated PROP, providing support for additional receptors or regulatory mechanisms in tasting PROP beyond threshold levels. (PMID:18209019)
• No significan correlation between mutations in this protein and papillary thyroid cancer in Turkey. (PMID:18393128)
• TAS2R38 single nucleotide polymorphisms are an important factor in determining nicotine dependence in African Americans. (PMID:18524836)
• Quantitative variations in PTC tasting ability in twins and to estimate heritability of PTC taste perception on the taste of twin data on males and females sexes separately. (PMID:18712160)
• Report genetic polymorphisms in the bitter-taste receptor gene TAS2R38, and adiposity in a genetically isolated population in Southern Italy. (PMID:18719631)
• TAS2R38 genetic variation, propylthiouracil phenotype, and sex interact to impact obesity risk in children. (PMID:19779476)
• TAS2R38 gene encodes a chemosensory receptor sensitive to thiourea compounds (PMID:19782709)
• filter paper tasting method strongly predicts TAS2R38 genotype, and the genotype-phenotype association is similar among ethnocultural groups. (PMID:20484932)
• the change in PROP bitter sensitivity which occurs over the lifespan (from bitter sensitive to less so) is more common in people with a particular haplotype combination, i.e., AVI/PAV heterozygotes (PMID:20594349)
• significant associations were seen in TAS2R38 for caries risk and/or protection. (PMID:20858777)
• Bitter receptor gene (TAS2R38) was identified to be responsible for phenylthiocarbamide (PTC) bitter sensitivity (PMID:21147709)
• The hTAS2R38 bitter taste receptor haplotypes were not associated with the daily intake of brassica vegetables (PMID:21338274)
• a suggestive association between the human bitter tasting phenotype and the risk of colorectal cancer (PMID:21674048)
• The data of this study showed how the combination of the TAS2R38 and gustin gene genotypes modulate PROP phenotype. (PMID:21712049)
• G145C polymorphism (rs713598) related to taste and food preferences and habits (PMID:21763010)
• study examined bitter taste genetics and whether variation in the TAS2R38 gene at three polymorphic loci (A49P, V262A and I296V) could alter dietary and systemic folate levels and dietary vitamin C intake (PMID:21769326)
• Report striking patterns of variation at TAS2R38, including a significant excess of novel rare nonsynonymous polymorphisms that recently arose only in Africa, high frequencies of haplotypes in Africa associated with intermediate bitter taste sensitivity. (PMID:22130969)
• Children with >/=1 bitter-sensitive allele (TAS2R38 PP or AP genotype) were more likely to have taken medication in solid formulation than were bitter-insensitive (AA genotype) children. (PMID:22440514)
• The localization of TAS2R38 is neither restricted to the cell surface nor particularly enriched at the level of the microvilli. (PMID:22792271)
• This study demonistrated that human TAS2R38 play the role of food preference behavior. (PMID:22794107)
• the TAS2R38 genotypes of schizophrenia patients was examined to determine whether the increased prevalence of nontasters in this patient population was indicative of a specific genetic association (PMID:22955840)
• T2R38 is an upper airway sentinel in innate defense and that genetic variation contributes to individual differences in susceptibility to respiratory infection. (PMID:23041624)
• genetic polymorphism is associated with chronic rhinosinusitis disease progression, necessity foe surgery and surgical outcome (PMID:23322450)
• PTC (phenylthiocarbamide) / PROP (6-n-propylthiouracil)-nontaster TAS2R38 genotype/haplotype was associated with height and weight but not with BMI, which may in turn have influenced the energy and carbohydrate intakes. (PMID:23535535)
• All psychophysical data were subsequently analyzed as a function of TAS2R38 genotype. (PMID:23761681)
• Evaluated the phenotypic variations at TAS2R38 gene locus in relation to PMS severity and adiposity measures among adult women. (PMID:23980393)
• results provide evidence that PAV-taste receptor type 2 member 38 (TAS2R38) expression amount correlates with individual differences in bitter sensory perception and diet (PMID:24025627)
• Gustin and TAS2R38 genotypes were associated with PROP threshold, but bitterness intensity was mostly determined by TAS2R38 genotypes. (PMID:24040192)
• genetic variation in TAS2R38 is related to individual body composition measures and may further influence consumer goods intake in the Sorbs possibly via individual sensitivity to bitter taste. (PMID:24312479)
• genetic polymorphism is associated with chronic rhinosinusitis in Canadien patients (PMID:24415641)

Cross-species orthologs

3 orthologs

Organism	Symbol	Gene ID
danio_rerio	tas2r200.2	ENSDARG00000074066
danio_rerio	tas2r200.1	ENSDARG00000079880
mus_musculus	Tas2r138	ENSMUSG00000058250

Paralogs (23): TAS2R8 (ENSG00000121314), TAS2R10 (ENSG00000121318), TAS2R7 (ENSG00000121377), TAS2R9 (ENSG00000121381), TAS2R3 (ENSG00000127362), TAS2R4 (ENSG00000127364), TAS2R5 (ENSG00000127366), TAS2R16 (ENSG00000128519), TAS2R1 (ENSG00000169777), TAS2R60 (ENSG00000185899), TAS2R42 (ENSG00000186136), TAS2R19 (ENSG00000212124), TAS2R50 (ENSG00000212126), TAS2R14 (ENSG00000212127), TAS2R13 (ENSG00000212128), TAS2R41 (ENSG00000221855), TAS2R40 (ENSG00000221937), TAS2R46 (ENSG00000226761), TAS2R39 (ENSG00000236398), TAS2R43 (ENSG00000255374), TAS2R20 (ENSG00000255837), TAS2R30 (ENSG00000256188), TAS2R31 (ENSG00000256436)

Protein

Protein identifiers

Taste receptor type 2 member 38 — P59533 (reviewed: P59533)

Alternative names: PTC bitter taste receptor, Taste receptor type 2 member 61

All UniProt accessions (1): P59533

UniProt curated annotations — full annotation on UniProt →

Function. Receptor that may play a role in the perception of bitterness and is gustducin-linked. May play a role in sensing the chemical composition of the gastrointestinal content. The activity of this receptor may stimulate alpha gustducin, mediate PLC-beta-2 activation and lead to the gating of TRPM5.

Subcellular location. Membrane.

Tissue specificity. Expressed in subsets of taste receptor cells of the tongue and exclusively in gustducin-positive cells. Expressed in testis.

Polymorphism. Variations in TAS2R38 are associated with the ability to taste phenylthiocarbamide (PTC tasting) [MIM:171200]; also called thiourea tasting. The ability to taste the substance PTC and a number of related substances is genetically controlled. Genetic studies have demonstrated complex inheritance for this trait. For some people (and some chimpanzees also), the chemical PTC tastes very bitter. For others, it is tasteless. Actually, substantial variation in taste sensitivity exists in human. Five haplotypes arising from three coding SNPs in the TAS2R38 gene are associated with distinct phenotypes of PTC taste sensitivity.

Miscellaneous. Most taste cells may be activated by a limited number of bitter compounds; individual taste cells can discriminate among bitter stimuli.

Similarity. Belongs to the G-protein coupled receptor T2R family.

RefSeq proteins (1): NP_789787* (*=MANE)

Domains & families (InterPro)

ID	Name	Type
IPR007960	TAS2R	Family
IPR030050	TAS2R38	Family

Pfam: PF05296

UniProt features (22 total): topological domain 8, transmembrane region 7, sequence variant 3, glycosylation site 2, chain 1, sequence conflict 1

Structure

Experimental structures (PDB)

0 structures.

Predicted structure (AlphaFold)

Model	pLDDT	Fraction very-high
AF-P59533-F1	81.86	0.36

Functional residue map

Curated UniProt residues grouped by drug-discovery relevance — catalytic, ligand-binding, modification, and mutation-validated positions. Source: UniProtKB sequence features.

Glycosylation sites (2): 89, 178

Function

Pathways and Gene Ontology

Reactome pathways

9 pathways

ID	Pathway
R-HSA-418594	G alpha (i) signalling events
R-HSA-420499	Class C/3 (Metabotropic glutamate/pheromone receptors)
R-HSA-9717207	Sensory perception of sweet, bitter, and umami (glutamate) taste
R-HSA-162582	Signal Transduction
R-HSA-372790	Signaling by GPCR
R-HSA-388396	GPCR downstream signalling
R-HSA-500792	GPCR ligand binding
R-HSA-9709957	Sensory Perception
R-HSA-9717189	Sensory perception of taste

MSigDB gene sets: 34 (showing top): GOBP_SENSORY_PERCEPTION_OF_CHEMICAL_STIMULUS, GOBP_DETECTION_OF_CHEMICAL_STIMULUS_INVOLVED_IN_SENSORY_PERCEPTION_OF_TASTE, GOBP_SENSORY_PERCEPTION_OF_TASTE, WTGAAAT_UNKNOWN, GOBP_DETECTION_OF_STIMULUS, GOBP_SENSORY_PERCEPTION, GOMF_TRANSMEMBRANE_SIGNALING_RECEPTOR_ACTIVITY, GOMF_BITTER_TASTE_RECEPTOR_ACTIVITY, GOMF_TASTE_RECEPTOR_ACTIVITY, GOMF_G_PROTEIN_COUPLED_RECEPTOR_ACTIVITY, GOBP_G_PROTEIN_COUPLED_RECEPTOR_SIGNALING_PATHWAY, GOBP_DETECTION_OF_STIMULUS_INVOLVED_IN_SENSORY_PERCEPTION, GOBP_SENSORY_PERCEPTION_OF_BITTER_TASTE, PEDRIOLI_MIR31_TARGETS_UP, E2F3_UP.V1_UP

GO Biological Process (4): detection of chemical stimulus involved in sensory perception of bitter taste (GO:0001580), signal transduction (GO:0007165), G protein-coupled receptor signaling pathway (GO:0007186), sensory perception of taste (GO:0050909)

GO Molecular Function (2): G protein-coupled receptor activity (GO:0004930), bitter taste receptor activity (GO:0033038)

GO Cellular Component (2): plasma membrane (GO:0005886), membrane (GO:0016020)

Reactome top-level categories

Rollup of top-6 pathways:

Category	Pathways
Signaling by GPCR	2
GPCR downstream signalling	1
GPCR ligand binding	1
Sensory perception of taste	1
Signal Transduction	1
Sensory Perception	1

GO top-level categories

Rollup of top GO terms by namespace:

Category	Terms
detection of chemical stimulus involved in sensory perception of taste	1
sensory perception of bitter taste	1
cell communication	1
cellular process	1
signaling	1
regulation of cellular process	1
cellular response to stimulus	1
G protein-coupled receptor activity	1
signal transduction	1
sensory perception of chemical stimulus	1
transmembrane signaling receptor activity	1
G protein-coupled receptor signaling pathway	1
detection of chemical stimulus involved in sensory perception of bitter taste	1
taste receptor activity	1
membrane	1
cell periphery	1
cellular anatomical structure	1

Protein interactions and networks

STRING

580 interactions, top by confidence (×1000):

Protein A	Protein B	Partner UniProt	Score
TAS2R38	GNAT3	A8MTJ3	953
TAS2R38	TAS2R16	Q9NYV7	939
TAS2R38	PLCB2	Q00722	878
TAS2R38	TAS1R2	Q8TE23	776
TAS2R38	TAS1R3	Q7RTX0	727
TAS2R38	TAS1R1	Q7RTX1	713
TAS2R38	CA6	P23280	664
TAS2R38	ANKK1	Q8NFD2	618
TAS2R38	CHRNA2	Q15822	560
TAS2R38	TRPM5	Q9NZQ8	557
TAS2R38	SLC17A6	Q9P2U8	542
TAS2R38	GABBR2	O75899	536
TAS2R38	DRD2	P14416	514
TAS2R38	SLC6A4	P31645	504
TAS2R38	ADH1B	P00325	496

IntAct

2 interactions, top by confidence:

A	B	Type	Score
TAS2R38	DUSP14	psi-mi:“MI:0914”(association)	0.350

BioGRID (3): DUSP14 (Affinity Capture-MS), RNF181 (Affinity Capture-MS), TAS2R38 (Affinity Capture-Western)

ESM2 similar proteins: A0A0R4IM31, A0A0R4IP11, P59532, P59533, P59536, P59551, Q2AB83, Q4VHE7, Q5J3F6, Q5J3L4, Q5J3L7, Q5J3M3, Q5J3M9, Q5J3N1, Q5Y4Z0, Q645S2, Q645U0, Q645U6, Q645U7, Q645Y3, Q645Z0, Q645Z1, Q646A4, Q646A5, Q646B2, Q646C7, Q646D0, Q646D5, Q646E6, Q646E9, Q646F3, Q67ER9, Q67ES2, Q67ES7, Q697L2, Q697L3, Q697L4, Q697L5, Q697L6, Q7TQA6

Diamond homologs: P0DSN6, P0DTE0, P59532, P59533, P59537, P59538, P59540, P59543, P59544, Q4VHE7, Q5Y4Y8, Q5Y4Z8, Q5Y500, Q645T0, Q645T3, Q645T6, Q645T7, Q645T9, Q645U2, Q645U9, Q645V3, Q645V4, Q645V7, Q645V8, Q645Y5, Q645Z6, Q646A1, Q646A2, Q646A7, Q646B4, Q646B8, Q646B9, Q646C0, Q646C2, Q646C4, Q646D2, Q646D6, Q646D8, Q646E0, Q646E1

SIGNOR signaling

0 interactions.

Disease & clinical

Clinical variants and AI predictions

ClinVar

61 variants total. Per-class counts are floors (≥ shown; pagination cap):

Classification	Count (floor)
Pathogenic	0
Likely pathogenic	0
Uncertain significance	54
Likely benign	4
Benign	1

Top pathogenic / likely-pathogenic (0)

SpliceAI

268 predictions. Top by Δscore:

Variant	Effect	Δscore
7:141973060:C:CT	acceptor_gain	0.8300
7:141973050:C:T	acceptor_gain	0.7200
7:141973061:A:T	acceptor_gain	0.7200
7:141973088:C:CT	acceptor_gain	0.7100
7:141973050:C:CT	acceptor_gain	0.7000
7:141973060:C:T	acceptor_gain	0.6700
7:141972919:C:CT	acceptor_gain	0.6600
7:141973097:C:CT	acceptor_gain	0.6600
7:141973098:A:T	acceptor_gain	0.6300
7:141973019:ATGTG:A	donor_gain	0.6100
7:141972929:C:CT	acceptor_gain	0.5800
7:141972971:T:TA	donor_gain	0.5700
7:141973090:CAGA:C	acceptor_gain	0.5700
7:141972930:A:T	acceptor_gain	0.5600
7:141972917:A:AC	donor_gain	0.5500
7:141973027:T:TA	donor_gain	0.5300
7:141973051:A:T	acceptor_gain	0.5300
7:141973028:C:A	donor_gain	0.5200
7:141973275:T:TA	donor_gain	0.5200
7:141973485:CA:C	acceptor_gain	0.5200
7:141973030:C:CT	acceptor_gain	0.5100
7:141973039:A:T	acceptor_gain	0.5100
7:141972816:C:CT	acceptor_gain	0.5000
7:141972881:A:T	acceptor_gain	0.5000
7:141973030:C:T	acceptor_gain	0.5000
7:141973043:A:T	acceptor_gain	0.5000
7:141973093:A:C	acceptor_gain	0.5000
7:141973576:C:CT	acceptor_gain	0.5000
7:141973577:A:T	acceptor_gain	0.5000
7:141973048:C:CT	acceptor_gain	0.4900

AlphaMissense

2198 scored. Top likely-pathogenic:

Variant	Protein change	am_pathogenicity
7:141973636:A:C	F18L	0.886
7:141973636:A:T	F18L	0.886
7:141973638:A:G	F18L	0.886
7:141973348:G:C	S114R	0.879
7:141973348:G:T	S114R	0.879
7:141973350:T:G	S114R	0.879
7:141973507:G:C	S61R	0.866
7:141973507:G:T	S61R	0.866
7:141973509:T:G	S61R	0.866
7:141973063:A:C	F209L	0.854
7:141973063:A:T	F209L	0.854
7:141973065:A:G	F209L	0.854
7:141973612:A:C	F26L	0.837
7:141973612:A:T	F26L	0.837
7:141973614:A:G	F26L	0.837
7:141973585:G:C	F35L	0.832
7:141973585:G:T	F35L	0.832
7:141973587:A:G	F35L	0.832
7:141973501:G:C	S63R	0.803
7:141973501:G:T	S63R	0.803
7:141973503:T:G	S63R	0.803
7:141973318:G:C	F124L	0.797
7:141973318:G:T	F124L	0.797
7:141973320:A:G	F124L	0.797
7:141972934:A:C	F252L	0.787
7:141972934:A:T	F252L	0.787
7:141972936:A:G	F252L	0.787
7:141972930:A:G	C254R	0.784
7:141973615:C:A	E25D	0.781
7:141973615:C:G	E25D	0.781

dbSNP variants (sampled 300 via entrez): RS1000902355 (7:141972963 T>C), RS1000912185 (7:141972754 C>A,G), RS1003402308 (7:141974608 T>A), RS1003863943 (7:141974425 G>T), RS1004859654 (7:141975100 C>T), RS1005212636 (7:141975474 A>T), RS1009160210 (7:141974049 G>A), RS1009328693 (7:141974357 G>A), RS1009793686 (7:141974145 A>C), RS1011678232 (7:141975687 A>G), RS1016796916 (7:141972294 G>A), RS1018386358 (7:141972411 A>T), RS1019375168 (7:141975110 T>A), RS1019811396 (7:141973736 C>A,G), RS1020796664 (7:141974155 G>A)

Disease associations

OMIM: gene MIM:607751 | disease phenotypes:

GenCC curated gene-disease

Disease	Classification	Inheritance
thiourea tasting	Limited	Autosomal dominant

Mondo (1): (MONDO:0044248)

Orphanet (0):

HPO phenotypes

2 total (2 of 2 shown, HPO-id order):

HPO	Term
HP:0000006	Autosomal dominant inheritance
HP:0000818	Abnormality of the endocrine system

GWAS associations

7 associations (top):

Study	Trait	p-value
GCST000746_1	Bitter taste response	2.000000e-104
GCST001961_2	Anorexia nervosa	2.000000e-07
GCST002144_1	Bitter taste perception	2.000000e-62
GCST008017_1	Bitter taste perception (6-n-propylthiouracil) in obesity with metabolic syndrome	4.000000e-19
GCST008019_1	Bitter taste perception (phenylthiocarbamide) in obesity with metabolic syndrome	1.000000e-17
GCST008522_38	Bitter alcoholic beverage consumption	2.000000e-10
GCST008529_8	Tea consumption	3.000000e-10

EFO canonical traits (2, from GWAS)

EFO ID	Trait name
EFO:0010092	bitter alcoholic beverage consumption measurement
EFO:0010091	tea consumption measurement

Drugs & pharmacology

Drug and pharmacology data

Is drug target: yes

ChEMBL targets (1): CHEMBL4523248 (SINGLE PROTEIN)

Molecules with ChEMBL bioactivity

2 molecules (phase ≥1), by development phase (incl. off-target/promiscuous compounds). Patent mentions across the top 20 by phase: 55,280 (via chembl_molecule»patent_compound — counts attach to the compound, not the gene–compound relationship, so off-target/promiscuous molecules can dominate).

Molecule	Name	Phase	Patents
CHEMBL1518	PROPYLTHIOURACIL	4	15,046
CHEMBL434	ISOPROTERENOL	4	40,234

PharmGKB: 1 entry (VIP=true, CPIC=false)

GtoPdb / IUPHAR curated pharmacology

(IUPHAR/BPS Guide to Pharmacology — expert-curated)

Target class: gpcr — Taste 2 receptors

Most potent curated ligand interactions (5 total), top 5:

Ligand	Action	Affinity	Parameter
phenylthiocarbamide	Agonist	5.68	pEC50
propylthiouracil	Agonist	5.68	pEC50
goitrin	Agonist	4.19	pEC50
methimazole	Agonist	4.01	pEC50
probenecid	Antagonist	3.68	pIC50

ChEMBL bioactivities

5 potent at pChembl≥5 of 9 total, top 5 by pChembl (potency: 10 = 0.1 nM, 6 = 1 µM).

pChembl	Type	Value	Unit	Molecule
8.31	EC50	4.9	nM	ISOPROTERENOL
6.30	EC50	500	nM	CHEMBL1212975
5.70	EC50	2000	nM	PHENYLTHIOUREA
5.70	EC50	2000	nM	PROPYLTHIOURACIL
5.64	EC50	2300	nM	CHEMBL275260

CTD chemical–gene interactions

10 total (human), top 10 by PubMed support.

Chemical	Actions (top 5)	PubMed papers
Propylthiouracil	decreases reaction, increases activity, affects activity, affects response to substance	4
Phenylthiourea	decreases reaction, increases activity, affects activity, affects response to substance	3
4-((diethylamino)sulfonyl)benzoic acid	decreases reaction, increases activity	1
CGP 52608	affects binding, increases reaction	1
Resveratrol	affects cotreatment, decreases expression	1
Benzo(a)pyrene	affects methylation, increases methylation	1
Formaldehyde	increases expression	1
Plant Extracts	affects cotreatment, decreases expression	1
Probenecid	decreases reaction, increases activity, decreases activity	1
Asbestos, Crocidolite	affects expression	1

ChEMBL screening assays

9 unique, capped per target: 9 functional

Representative assays (with source publication via chembl_document):

Assay ID	Type	Description	Source paper
CHEMBL4419007	Functional	Agonist activity at recombinant human N-terminal rat ST3 receptor-fused TAS2R38 expressed in HEK293T cells co-expressing Galpha16gust44 assessed as increase in intracellular calcium level at 100 uM by FLIPR assay	Methods of identifying antagonists of the hTAS2R46 bitter taste receptor

Clinical trials (associated diseases)

0 trials via MONDO — disease-level, not drug-specific.