title: TRPV1 channels are functionally coupled with BK(mSlo1) channels in rat dorsal root ganglion (DRG) neurons.
abstract: The transient receptor potential vanilloid receptor 1 (TRPV1) channel is a nonselective cation channel activated by a variety of exogenous and endogenous physical and chemical stimuli, such as temperature (≥42 °C), capsaicin, a pungent compound in hot chili peppers, and allyl isothiocyanate. Large-conductance calcium- and voltage-activated potassium (BK) channels regulate the electric activities and neurotransmitter releases in excitable cells, responding to changes in membrane potentials and elevation of cytosolic calcium ions (Ca(2+)). However, it is unknown whether the TRPV1 channels are coupled with the BK channels. Using patch-clamp recording combined with an infrared laser device, we found that BK channels could be activated at 0 mV by a Ca(2+) influx through TRPV1 channels not the intracellular calcium stores in submilliseconds. The local calcium concentration around BK is estimated over 10 μM. The crosstalk could be affected by 10 mM BAPTA, whereas 5 mM EGTA was ineffectual. Fluorescence and co-immunoprecipitation experiments also showed that BK and TRPV1 were able to form a TRPV1-BK complex. Furthermore, we demonstrated that the TRPV1-BK coupling also occurs in dosal root ganglion (DRG) cells, which plays a critical physiological role in regulating the "pain" signal transduction pathway in the peripheral nervous system.
authors.affiliation: Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei, China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Wu
authors.forename: Yongfeng
authors.initials: Y
authors.lastname: Liu
authors.forename: Panpan
authors.initials: P
authors.lastname: Hou
authors.forename: Zonghe
authors.initials: Z
authors.lastname: Yan
authors.forename: Wenjuan
authors.initials: W
authors.lastname: Kong
authors.forename: Beiying
authors.initials: B
authors.lastname: Liu
authors.forename: Xia
authors.initials: X
authors.lastname: Li
authors.forename: Jing
authors.initials: J
authors.lastname: Yao
authors.forename: Yuexuan
authors.initials: Y
authors.lastname: Zhang
authors.forename: Feng
authors.initials: F
authors.lastname: Qin
authors.forename: Jiuping
authors.initials: J
authors.lastname: Ding
mesh_terms: D000818:Animals; D002460:Cell Line; D004594:Electrophysiology; D005727:Ganglia, Spinal / Q000166:cytology*; D006801:Humans; D047468:Immunoprecipitation; D051037:Large-Conductance Calcium-Activated Potassium Channel alpha Subunits / Q000378:metabolism*; D008297:Male; D008564:Membrane Potentials / Q000502:physiology; D009474:Neurons / Q000378:metabolism*; D011485:Protein Binding; D051381:Rats; D017208:Rats, Wistar; D050916:TRPV Cation Channels / Q000378:metabolism*
chemical_list: D051037:Large-Conductance Calcium-Activated Potassium Channel alpha Subunits; D050916:TRPV Cation Channels; C493922:Trpv1 protein, rat