TAS2R1


Taste receptor type 2 member 1 is a protein that in humans is encoded by the TAS2R1 gene. It belongs to the G protein-coupled receptor family and is related to class A-like GPCRs, they contain 7 transmembrane helix bundles and short N-terminus loop. Furthermore, TAS2R1 is member of the 25 known human bitter taste receptors, which enable the perception of bitter taste in the mouth cavity. Increasing evidence indicates a functional role of TAS2Rs in extra-oral tissues.

Expression and function

Extra-oral roles of TAS2Rs

Bitter taste receptors are expressed in taste receptor cells, which organized into taste buds on the papillae of the tongue and palate epithelium.
In addition, TAS2Rs were found to be expressed in extra-oral tissues, e.g. brain, lungs, gastrointestinal tract, etc. So far, less is known about their function however, for example it was shown that:
Based on a recent homology model from several conserved motifs, which are counterparts to Class A GPCRs were found:
Numbering is according to the Balleros-Weinstein system.
Unlike in Class A GPCRs, in transmembrane helix 4 no DRY motif was found as well as position 6.50 is not conserved.

''TAS2R1'' gene

This gene encodes a member of a family of candidate taste receptors that are members of the G protein-coupled receptor superfamily and that are specifically expressed by taste receptor cells of the tongue and palate epithelia. This intronless taste receptor gene encodes a 7-transmembrane receptor protein, functioning as a bitter taste receptor.

SNPs

In T2R1 two SNPs are known in R111H and R206W.

Transcription Factors

So far, AML1a, AP-1, AREB6, FOXL1, IRF-7A, Lmo2, NF-E2, NF-E2 p45 were found as the top transcription factor binding sites by QIAGEN in the .

Mutagenesis">Site-directed mutagenesis">Mutagenesis data

Several mutations have been shown to influence binding of a ligand to TAS2R1 :
Receptor regionBW numberResidueReference
TM11.5N24doi: 10.1021/acs.jctc.5b00472 doi: 10.1074/jbc.M111.246983
TM11.53I27doi: 10.1021/acs.jctc.5b00472 doi: 10.1074/jbc.M111.246983
TM22.5R55doi: 10.1021/acs.jctc.5b00472 doi: 10.1074/jbc.M111.246983
TM22.56F61doi: 10.1074/jbc.M111.246983
TM22.61N66doi: 10.3389/fmolb.2017.00063 doi: 10.1021/acs.jctc.5b00472 doi: 10.1016/bs.mcb.2015.10.005 doi: 10.1074/jbc.M111.246983
ECL1E74doi: 10.3389/fmolb.2017.00063
TM33.32L85doi: 10.1016/bs.mcb.2015.10.005 doi: 10.3109/10799893.2011.578141
TM33.33L86doi: 10.1016/bs.mcb.2015.10.005 doi: 10.3109/10799893.2011.578141
TM33.36N89doi: 10.1016/bs.mcb.2015.10.005 doi: 10.1074/jbc.M111.246983 doi: doi: 10.1021/acs.jctc.5b00472 doi: 10.1074/jbc.M111.246983
TM33.37E90doi: 10.1016/bs.mcb.2015.10.005 doi: 10.3109/10799893.2011.578141
TM33.41W94doi: 10.1021/acs.jctc.5b00472 doi: 10.1074/jbc.M111.246983
TM33.46L99doi: 10.1021/acs.jctc.5b00472 doi: 10.1074/jbc.M111.246983
TM55.46E182doi: 10.1016/bs.mcb.2015.10.005 doi: 10.3109/10799893.2011.578141
TM55.61L197doi: 10.1021/acs.jctc.5b00472 doi: 10.1074/jbc.M111.246983
TM55.64S200doi: 10.1021/acs.jctc.5b00472 doi: 10.1074/jbc.M111.246983
TM55.65L201doi: 10.1021/acs.jctc.5b00472 doi: 10.1074/jbc.M111.246983
TM77.39I263doi: 10.1016/bs.mcb.2015.10.005 doi: 10.3109/10799893.2011.578141
TM77.49H273doi: 10.1021/acs.jctc.5b00472 doi: 10.1074/jbc.M111.246983
TM77.53L277doi: 10.1021/acs.jctc.5b00472 doi: 10.1074/jbc.M111.246983
TM77.54I278doi: 10.1021/acs.jctc.5b00472 doi: 10.1074/jbc.M111.246983

Ligands

Up to now, 39 ligands for T2R1 were identified in BitterDB, among them L-amino acids, peptides, humulones, small molecules etc.