TRPM1
Function
Constitutively open nonselective divalent cation-conducting channels which mediate the influx of Ca(2+), Mg(2+), Mn(2+), Ba(2+), and Ni(2+) into the cytoplasm, leading to membrane depolarization (PubMed:11535825, PubMed:19436059, PubMed:21278253). Impermeable to zinc ions (PubMed:21278253). In addition, forms heteromultimeric ion channels with TRPM3 which are permeable for calcium and zinc ions (PubMed:21278253). Plays an essential role for the depolarizing photoresponse of retinal ON bipolar cells (PubMed:19878917, PubMed:19896109). In the dark, tonic release of glutamate activates the G-protein coupled receptor for glutamate, GRM6, its activation induces the release of G(o) protein and the beta-gamma G protein dimer. Both subunits can interact and inactivate the TRPM1 channel. A light onset, induces decrease in glutamate release and deactivation of GRM6 leading to channel opening and membrane depolarization (By similarity). May play a role in metastasis suppression (PubMed:9537257).
Involvement in disease
Night blindness, congenital stationary, 1C
CSNB1C
A non-progressive retinal disorder characterized by impaired night vision, often associated with nystagmus and myopia.
None
The disease is caused by variants affecting the gene represented in this entry.
Sequence Similarities
Belongs to the transient receptor (TC 1.A.4) family. LTrpC subfamily. TRPM1 sub-subfamily.
Tissue Specificity
Expressed in the retina where it localizes to the outer plexiform layer. Specifically, it is expressed in retinal bipolar cells (BPCs) of the ON subtype (PubMed:30027108). Highly expressed in benign melanocytic nevi and diffusely expressed in various in situ melanomas, but not detected in melanoma metastases. Also expressed in melanocytes and pigmented metastatic melanoma cell lines. In melanocytes expression appears to be regulated at the level of transcription and mRNA processing.
Cellular localization
- Cell membrane
- Multi-pass membrane protein
- Endoplasmic reticulum membrane
- Multi-pass membrane protein
- Cell projection
- Axon
- In ON-bipolar cells is intracellular and located predominantly in the ER, and not at the plasma membrane or Golgi apparatus.
Alternative names
LTRPC1, MLSN, MLSN1, TRPM1, Transient receptor potential cation channel subfamily M member 1, Long transient receptor potential channel 1, Melastatin-1, LTrpC1