Gene and Protein Information
Species	TM	AA	Chromosomal Location	Gene Symbol	Gene Name	Reference
Human	4	456	3q27.1	HTR3E	5-hydroxytryptamine receptor 3E	2-4

Previous and Unofficial Names

HTR3C1long | 5-hydroxytryptamine (serotonin) receptor 3E, ionotropic

Database Links
Alphafold	A5X5Y0 (Hs)
CATH/Gene3D	2.70.170.10
ChEMBL Target	CHEMBL4296087 (Hs)
Ensembl Gene	ENSG00000186038 (Hs)
Entrez Gene	285242 (Hs)
Human Protein Atlas	ENSG00000186038 (Hs)
KEGG Gene	hsa:285242 (Hs)
OMIM	610123 (Hs)
Pharos	A5X5Y0 (Hs)
RefSeq Nucleotide	NM_182589 (Hs)
RefSeq Protein	NP_872395 (Hs)
UniProtKB	A5X5Y0 (Hs)
Wikipedia	HTR3E (Hs)

Natural/Endogenous Ligands
5-hydroxytryptamine

Tissue Distribution
Colon, intestine. Species:  Human Technique:  RT-PCR References:  3
Small intestine >> spinal cord and retina. Species:  Human Technique:  RT-PCR References:  2
Essentially ubiquitous, relatively high levels of expression in dorsal root ganglia, pituitary, brain, kidney and thyroid Species:  Human Technique:  RT-PCR References:  1

Biologically Significant Variants
Type:  Splice variant Species:  Human Description:  Canonical isoform. Amino acids:  471 Nucleotide accession:  NM_182589 Protein accession:  NP_872395 References:  2-3
Type:  Splice variant Species:  Human Description:  The human 5-HT3E subunit occurs as a variant that has unofficially been termed 5-HT3E(A) (or HTR3C1short). Amino acids:  456 Nucleotide accession:  DQ644022 Protein accession:  ABG35128 References:  4

General Comments

The 5-HT3E subunit is absent from the rodent genome [1-3]. The human 5-HT3E subunit does not function as a homomer [1,4]. Co-expression with the 5-HT3A subunit has been found to mandatory for the expression of the 5-HT3E subunit at the cell surface in one study [4], but not in a second [1]. Co-assembly of the 5-HT3A and 5-HT3E subunits when heterologously expressed in HEK-293 cells has been demonstrated by immunoprecipitation [4]. Co-expression of the 5-HT3A and 5-HT3E subunits does not alter the potency of agonists and antagonists observed for homopentameric 5-HT3A receptors [1,4].