Taste receptors for bitter substances (T2Rs/TAS2Rs) belong to the family of G-protein coupled receptors and are related to class A-like GPCRs. There are 25 known T2Rs in humans responsible for bitter taste perception. Taste receptor type 2 member 46 is a protein that in humans is encoded by the TAS2R46 gene.

Gene

TAS2R46 gene (Taste receptor type 2 member 46) is a Protein Coding gene. This gene maps to the taste receptor gene cluster on chromosome 12. hTAS2R46 is a bitter receptor broadly tuned to sesquiterpene lactones, related clerodane diterpenoids, labdane diterpenes and more.

Structure

In 2022, the solved structure of Tas2r46 was published in the scientific journal Science making it the first Tas2r with a solved structure. The structure of Tas2r46 was solved with cryo-EM and can be downloaded in the Protein Data Bank, under the following names: 7xp6- Cryo-EM structure of a class T GPCR in active state,7xp5- Cryo-EM structure of a class T GPCR in ligand-free state,7xp4- Cryo-EM structure of a class T GPCR in apo state. There is also a prediction structure available in Alphafold, named Taste receptor type 2 member 46 this is a computational prediction and not an experimental structure.

Tissue distribution

TAS2R46 was shown to be expressed in other tissues in the human body apart from the oral cavity including human bone marrow stromal-derived cells (MSC) and their relatives, vascular smooth muscle cells (VSMC).

Ligands

Up to now, 68 ligands were identified for T2R46 and are summarized in Some of TAS2R46 ligands are approved as drugs two of the more known ligands of TAS2R46 are Atropine and Strychnine. Strychnine is known as a strong poison that suppresses the nerve system. Strychnine even makes an appearance in the famous Agatha Christie novel The Mysterious Affair at Styles. Atropine injection is used to treat heart rate disorders of various types, and is used in drops to treat lazy eye condition.

Clinical significance

TAS2R46 was associated with Inflammatory Bowel Disease

SNPs

Obtained from

Known mutations

Known mutations of TAS2R46 include the following: