Identification and classification of a new TRPM3 variant (γ subtype)

The journal of physiological sciences

article

Kunitoshi Uchida¹  Naomi Fukuta²  Jun Yamazaki¹  Makoto Tominaga² 

[1] Departments of Physiological Science and Molecular Biology and Morphological Biology, Fukuoka Dental College;Division of Cell Signaling, National Institute for Physiological Sciences, Okazaki Institute for Integrative Bioscience, National Institutes of Natural Sciences;Department of Veterinary Medicine, Nihon University College of Bioresource Sciences;Department of Physiological Sciences, SOKENDAI (The Graduated University for Advanced Studies);Thermal Biology Group, Exploratory Research Center on Life and Living Systems, National Institutes of Natural Sciences;Institute for Environmental and Gender-Specific Medicine, Juntendo University

关键词: TRPM3 channel;    Variant;    Ca 2+ -imaging;    Oocyte recording;    Thermosensitivity;   

DOI  :  10.1007/s12576-019-00677-6

来源: Springer

【 摘 要 】

TRPM3 is a non-selective cation channel that is activated by neural steroids such as pregnenolone sulfate, nifedipine, and clotrimazole. Despite the number of TRPM3 variants, few reports have described functional analyses of these different TRPM3 types. Here we identified a new TRPM variant from mouse dorsal root ganglion, termed TRPM3γ3. We classified TRPM3γ3 and another known variant (variant 6) into the γ subtype, and analyzed the TRPM3γ variants. mRNA expression of TRPM3γ was higher than that of TRPM3α variants in the mouse dorsal root ganglion. In Ca2+-imaging of HEK293 cells expressing either the TRPM3γ variants or TRPM3α2, increases in cytosolic Ca2+ concentrations ([Ca2+]i) induced by pregnenolone sulfate or nifedipine were smaller in cells expressing the TRPM3γ variants compared to those expressing TRPM3α2. On the other hand, co-expression of TRPM3γ variants had no effect on [Ca2+]i increases induced by pregnenolone sulfate or nifedipine treatment of HEK293 cells expressing TRPM3α2. In Xenopus oocytes, small responses of TRPM3γ variants to chemical agonists compared to TRPM3α2 were also observed. Interestingly, Xenopus oocytes expressing TRPM3α2 displayed heat-evoked currents with clear thresholds of about 40 °C that were larger than those evoked in oocytes expressing TRPM3γ variants. Overall, these findings indicate that TRPM3γ variants have low channel activity compared to TRPM3α.

【 授权许可】

Unknown