The molecular basis of the thermal sensitivity temperature-sensitive channels appears to arise from a specific protein domain rather than integration global effects. Using systematic chimeric analysis, we show that N-terminal region connects ankyrin repeats first transmembrane segment is crucial for temperature sensing in heat-activated vanilloid receptor channels. Changing this both transformed temperature-insensitive isoforms into and significantly perturbed wild-type Swapping other...

Cold is detected by a small subpopulation of peripheral thermoreceptors. TRPM8, cloned menthol- and cold-sensitive ion channel, has been suggested to mediate cold transduction in the innocuous range. The channel shows robust response whole-cell recordings but exhibits markedly reduced activity excised membrane patches. Here we report that phosphatidylinositol 4,5-bisphosphate (PIP 2 ) an essential regulator function. rundown prevented lipid phosphatase inhibitors. Application exogenous PIP...

We present a maximum likelihood method for the modelling of aggregated Markov processes. The utilizes joint probability density observed dwell time sequence as likelihood. A forward–backward recursive procedure is developed efficient computation function and its derivatives with respect to model parameters. Based on calculated forward backward vectors, analytical formulae are derived. exploits variable metric optimizer search space. It converges rapidly numerically stable. Numerical examples...

Patch-clamp recording provides an unprecedented means for study of detailed kinetics ion channels at the single molecule level. Analysis recordings often begins with idealization noisy into continuous dwell-time sequences. Success analysis is contingent on accuracy idealization. I present here a statistical procedure based hidden Markov modeling and k-means segmentation. The approach assumes scheme involving discrete conformational transitions channel white background noise contamination...

Capsaicin and other naturally occurring pungent molecules have long been used as topical analgesics to treat a variety of chronic pain conditions. The analgesic effects these compounds involve long-term desensitization nociceptors after strong stimulation. To elucidate the underlying mechanisms, we studied recovery from vanilloid receptor TRPV1. We showed that prolonged applications capsaicin led nearly complete channel its functional required high concentration intracellular ATP....

Multimodal gating is an essential feature of many TRP ion channels, enabling them to respond complex cellular environments. TRPV1, a pain receptor involved in nociception at the peripheral nerve terminals, can be activated by range physical and chemical stimuli (e.g., capsaicin, proton, heat) further sensitized proinflammatory substances. How single achieves this multiplicity functionality poorly understood molecular level. Here, we investigated structural basis proton activation TRPV1....

Vanilloid receptors of the transient receptor potential family have functions in thermal sensation and nociception. Among them, vanilloid (TRPV)3 displays a unique property by which repeated stimulation causes successive increases its activity. The has been known as sensitization is observed both native cells heterologously expressing TRPV3. Transient intracellular calcium levels implicated to play key role this process mediating interaction calmodulin with channel. In support mechanism,...

Significance Thermal TRP channels are principal molecular entities of transducing thermal and noxious stimuli. The mechanisms by which they detect temperature remain elusive, however. Our others’ recent studies show that channels, such as the vanilloid receptor transient potential 3 (TRPV3), strongly use-dependent. Here, exploring this distinct feature using fast jumps, we have identified a basis for temperature-dependent gating ion channels.

Adaptation is a common feature of many sensory systems. But its occurrence to pain sensation has remained elusive. Here we address the problem at receptor level and show that capsaicin ion channel TRPV1, which mediates nociception peripheral nerve terminals, possesses properties essential adaptation responses. Ca2+ influx following opening caused profound shift (∼14-fold) agonist sensitivity, but did not alter maximum attainable current. The was adequate render irresponsive normally...

The vanilloid receptor TRPV1 is an exquisite nociceptive sensor of noxious heat, but its temperature-sensing mechanism yet to define. Thermodynamics dictate that this channel must undergo unusually energetic allosteric transition. Thus, it fundamental importance measure directly the energetics transition in order properly decipher mechanism. Previously, using submillisecond temperature jumps and patch-clamp recording, we estimated heat activation for opening incurs enthalpy change on 100...

Capsaicin ion channels are highly expressed in peripheral nervous terminals and involved pain thermal sensations. One characteristic of the cloned VR1 receptor is its multimodal responses to various types noxious stimuli. The channel independently activated by capsaicin related vanilloids at submicromolar range, heat above 40°C, protons pH below 6.5. Furthermore, simultaneous applications two or more stimuli lead cross sensitization receptor, with an apparent increase sensitivity any...

The transient receptor potential (TRP) channels act as key sensors of various chemical and physical stimuli in eukaryotic cells. Despite years study, the molecular mechanisms TRP channel activation remain unclear. To elucidate structural, dynamic, energetic basis gating TRPV1 (a founding member TRPV subfamily), we performed coarse-grained modeling all-atom dynamics (MD) simulation based on recently solved high resolution structures open closed form TRPV1. Our normal mode analysis captures...

The kinetic properties of main and subconductance states a mutant mouse N-methyl-d-aspartate (NMDA) receptor channel were examined. Recombinant receptors made ζ-ε2 (NR1-NR2B) subunits having asparagine-to-glutamine mutations in the M2 segment (ζN598Q /ε2N589Q) expressed Xenopus oocytes. Single currents recorded from outside-out patches analyzed using hidden Markov model techniques. In Ca2+-free solutions, an open occupies conductance (93 pS) (62 with about equal probability. There are both...