High impact information on TRPM3

• Alternative splicing switches the divalent cation selectivity of TRPM3 channels [1].
• From its function and expression in human kidney, we propose a role of TRPM3 in renal Ca2+ homeostasis [2].
• Depletion of intracellular Ca2+ stores by lowering extracellular Ca2+ concentration and treatment with the Ca2+-ATPase inhibitor thapsigargin or the muscarinic receptor agonist carbachol further augmented hTRPM3-mediated Ca2+ entry [3].
• The nonselective Ca2+ channel blocker, lanthanide gadolinium (Gd3+), partially inhibited hTRPM3-mediated Ca2+ entry [3].
• In situ hybridization in human kidney demonstrated that hTRPM3 mRNA expression is predominantly found in the collecting tubular epithelium [3].

Biological context of TRPM3

• Utilizing a bioinformatics approach, we have identified the full-length human TRPM3 (hTRPM3) as a member of the TRP family [3].

Anatomical context of TRPM3

• Whereas miR-124a is expressed in neurons, miR-9 is expressed in neural progenitors and some neurons, and miR-204 is expressed in the choroid plexus, retinal pigment epithelium, and ciliary body. miR-204 is located in an intron of the TRPM3 gene, and the TRPM3 mRNA is coexpressed with miR-204 in the choroid plexus [4].
• We also confirmed the presence of TRPM7 and absence of TRPM3 in U937 cells [5].
• In addition, the effect of M-CSF on ovarian macrophages was investigated using immunohistochemistry with mouse anti-rat macrophage monoclonal antibody, TRPM-3 [6].

Associations of TRPM3 with chemical compounds

• Although sphingosine-1-phosphate and ceramides had no effect, two structural analogs of sphingosine, dihydro-D-erythro-sphingosine and N,N-dimethyl-D-erythro-sphingosine, also activated TRPM3 [7].
• Activation of the melastatin-related cation channel TRPM3 [corrected] by D-erythro-sphingosine [7].
• Heterologously expressed TRPM3 channels are constitutively active, have an outwardly rectifying current-voltage relationship and are inhibited by intracellular Mg(2+) ions [8].

Other interactions of TRPM3

• TRPM3, a member of the melastatin-like transient receptor potential channel subfamily (TRPM), is predominantly expressed in human kidney and brain [7].
• 6 2-APB also blocks TRPC6 and TRPM3 expressed in HEK-293 cells, but not TRPM2 [9].
• TRPM2, TRPM3 and TRPM8 mediate a direct influx of Ca(2+) in response to specific stimuli [10].

Analytical, diagnostic and therapeutic context of TRPM3

• Using measurements with the Ca2+-sensitive fluorescent dye fura-2 and the whole-cell patch-clamp technique, we found that D-erythro-sphingosine, a metabolite arising during the de novo synthesis of cellular sphingolipids, activated TRPM3 [7].

References