TRESK Background K+ Channel Is Inhibited by PAR-1/MARK Microtubule Affinity-Regulating Kinases in Xenopus Oocytes

Abstract

TRESK (TWIK-related spinal cord K+ channel, KCNK18) is a major background K+ channel of sensory neurons. Dominant-negative mutation of TRESK is linked to familial migraine. This important two-pore domain K+ channel is uniquely activated by calcineurin. The calcium/calmodulin-dependent protein phosphatase directly binds to the channel and activates TRESK current several-fold in Xenopus oocytes and HEK293 cells. We have recently shown that the kinase, which is responsible for the basal inhibition of the K+ current, is sensitive to the adaptor protein 14-3-3. Therefore we have examined the effect of the 14-3-3-inhibited PAR-1/MARK, microtubule-associated-protein/microtubule affinity-regulating kinase on TRESK in the Xenopus oocyte expression system. MARK1, MARK2 and MARK3 accelerated the return of TRESK current to the resting state after the calcium-dependent activation. Several other serine-threonine kinase types, generally involved in the modulation of other ion channels, failed to influence TRESK current recovery. MARK2 phosphorylated the primary determinant of regulation, the cluster of three adjacent serine residues (S274, 276 and 279) in the intracellular loop of mouse TRESK. In contrast, serine 264, the 14-3-3-binding site of TRESK, was not phosphorylated by the kinase. Thus MARK2 selectively inhibits TRESK activity via the S274/276/279 cluster, but does not affect the direct recruitment of 14-3-3 to the channel. TRESK is the first example of an ion channel phosphorylated by the dynamically membrane-localized MARK kinases, also known as general determinants of cellular polarity. These results raise the possibility that microtubule dynamics is coupled to the regulation of excitability in the neurons, which express TRESK background potassium channel.

Intrathecal TRESK gene recombinant adenovirus attenuates spared nerve injury-induced neuropathic pain in rats

“…TRESK, a two-pore domain (K2P) potassium channel, is associated with general anesthesia [2]. Recent studies indicate that TRESK plays a critical role in migraine with aura, inflammation-induced pain, and nerve injuryinduced pain [3][4][5]. TRESK is expressed abundantly in dorsal root ganglia [6], and was shown in our previous study that downregulating of TRESK background current in dorsal root ganglia contributed to neuropathic pain in spared nerve injury models [7].…”

The LQLP Calcineurin Docking Site Is a Major Determinant of the Calcium-dependent Activation of Human TRESK Background K+ Channel

“…The membranes were washed once after blocking and four to six times after the antibodies for 5-20 min in PBS-T. Preparation of the thioredoxin-hexahistidine-tagged constitutively active MARK2 kinase, containing the T208E phospho-mimicking activator loop mutation, has previously been described (8).…”

“…Microtubule-affinity regulating (MARK) kinases are currently the only known enzymes that phosphorylate the other two serines of functional importance. Accordingly, the overexpression of MARK accelerates the return of the K ϩ current to the resting state after the calcium-dependent activation of TRESK in Xenopus oocytes (8).…”

“…We previously reported that the calcium/calmodulin-dependent protein phosphatase calcineurin mediates the effect (6). Three serine residues (Ser-264, Ser-274, and Ser-276) have been identified by alanine-scanning mutagenesis as the putative targets of the phosphatase in the mouse channel (6,8,10). These residues are also conserved in human TRESK as Ser-252, Ser-262, and Ser-264.…”

Prion Protein Signaling in the Nervous System—A Review and Perspective

“…Calcium ion flux, as well as cytoplasmic ROS, has the potential to influence the mitochondrial retrograde signaling response (reviewed by Butow and Avadhani). 123 In addition, PrP C has been linked to both protein complex 14-3-3 100 and calcineurin B, 83 both of which are known to directly affect the regulation of the K + leak channel K2P, TRESK, which determines resting membrane excitability 124 and is the only K2P channel upregulated by a Ca 2+ -dependant pathway. This may give PrP C an indirect role in this ion channel and therefore cellular electrical excitability.…”