Ion channel regulation by protein S-acylation

Shipston, Michael J.

doi:10.1085/jgp.201411176

Cited by 59 publications

(65 citation statements)

References 136 publications

(246 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…These data imply that t-SNARE acylation is highly dynamic in platelets and cycles due to the actions of PATs and APTs, much like phosphorylation is controlled by kinases and phosphatases. While the cycling of acyl groups has been reported on other proteins in other cells (38)(39)(40), our data are the first to demonstrate its importance in platelets. …”

supporting

confidence: 60%

Dynamic cycling of t-SNARE acylation regulates platelet exocytosis

Zhang

Huang²,

Chen

et al. 2018

Journal of Biological Chemistry

View full text Add to dashboard Cite

ABSTRACT:Platelets regulate vascular integrity by secreting a host of molecules that promote hemostasis and its sequelae. Given the importance of platelet exocytosis, it is critical to understand how it is controlled. The t-SNAREs, SNAP-23 and syntaxin-11, lack classical transmembrane domains (TMDs), yet both are associated with platelet membranes and redistributed into cholesterol-dependent, lipid rafts when platelets were activated. Using metabolic labeling and hydroxylamine/HCl (HA) treatment, we showed that both contain thioester-linked acyl groups. Mass spectrometry mapping further showed that syntaxin-11 was modified on Cysteine 275, 279, 280, 282, 283 and 285, was modified on Cysteine 79, 80, 83, 85, and 87. Interestingly, metabolic labeling studies showed incorporation of [ 3 H]-palmitate into the t-SNAREs increased though the protein levels were unchanged, suggesting that acylation turns over on the two t-SNAREs in resting platelets. Exogenously added fatty acids did compete with [ 3 H]-palmitate for t-SNARE labeling. To determine the effects of acylation, we measured aggregation, ADP/ATP release as well as P-selectin exposure in platelets treated with the acyl-transferase inhibitor, cerulenin, or the thioesterase inhibitor, palmostatin B. We found that cerulenin pretreatment inhibited t-SNARE acylation and platelet function in a dose-and time-dependent manner while palmostatin B had no detectable effect. Interestingly, pretreatment with palmostatin B blocked the inhibitory effects of cerulenin suggesting that maintaining the acylation state is important for platelet function. Thus, our work shows that t-SNARE acylation is actively cycling in platelets and suggests that the enzymes regulating protein acylation could be potential targets to control platelet exocytosis in vivo.Platelet exocytosis is critical for hemostasis; however, it is increasingly obvious that platelets secrete components with (8)(9)(10)(11)(12)(13)(14). Further studies defined specific SNARE regulators, which control when and where the v-and t-SNAREs interact. Aside from the role that I κ B Kinase-mediated phosphorylation plays in controlling SNAP-23/syntaxin-11 association (15), little is known about other post-translational modifications and their effects on the platelet exocytosis.Despite their importance to secretion, neither SNAP-23 nor syntaxin-11 contains a classical transmembrane domain (TMD), nor any identifiable CAAX motifs. Instead, both proteins contain cysteine-rich regions: human syntaxin-11 has 8 cysteines with 6 at its C-terminus, and SNAP-23 contains 6 cysteines with 5 in a central domain. These cysteine-rich regions have been shown, in some cells, to be important for membrane association and are potential sites for S-acylation (16)(17)(18)(19)(20) (27,28).Past studies have shown that acylation occurs in platelets (29). Dowal et al. characterized over 200 proteins in the platelet "palmitoylome", many of which appear to be involved in platelet signaling pathways (30). Consistently, Sim et al. showed that PAT-inhibit...

show abstract

supporting

confidence: 60%

Dynamic cycling of t-SNARE acylation regulates platelet exocytosis

Zhang

Huang²,

Chen

et al. 2018

Journal of Biological Chemistry

View full text Add to dashboard Cite

show abstract

“…8 years later, in 1987, the first palmitoylated ion channel, rodent voltage-gated Na ϩ channel, was characterized (44). Since then, more than 50 different ion channels have been experimentally demonstrated to be palmitoylated (31). Increasing evidence has so far indicated that palmitoylation may regulate either the channel's membrane density or single channel activity (31).…”

Section: Discussionmentioning

confidence: 99%

“…Recently, more and more ion channel proteins, such as the large conductance voltage-gated potassium channel and TRPML1, have been reported to be post-translationally modified by palmitoylation at cysteine residues to regulate channel trafficking and/or function (31)(32)(33). We then investigated whether TRPP3 Cys-38 is a palmitoylation site.…”

Section: -E)mentioning

confidence: 99%

“…In some membrane proteins, such as G-protein coupled receptors, palmitoylation of a C-terminal domain has led to the formation of an additional intracellular loop linked to receptor de-sensitization (28 -30). An increasing number of ion channel proteins has been reported to undergo palmitoylation as a way of controlling the anchorage of an intracellular domain to membranes (31). An interplay between palmitoylation and phosphorylation has recently been recognized as a new mechanism of regulating the trafficking or function of ion channels (31).…”

mentioning

confidence: 99%

“…An increasing number of ion channel proteins has been reported to undergo palmitoylation as a way of controlling the anchorage of an intracellular domain to membranes (31). An interplay between palmitoylation and phosphorylation has recently been recognized as a new mechanism of regulating the trafficking or function of ion channels (31). Among them, TRPML1 has been reported to undergo palmitoylation and de-phosphorylation, following histamine stimulation of gastric acid secretion, which may underlie the mechanism of its endocytosis (32,33).…”

mentioning

confidence: 99%

See 2 more Smart Citations

Regulation of TRPP3 Channel Function by N-terminal Domain Palmitoylation and Phosphorylation

Zheng¹,

Yang²,

Beauchamp

et al. 2016

Journal of Biological Chemistry

View full text Add to dashboard Cite

Edited by Roger ColbranTransient receptor potential polycystin-3 (TRPP3) is a cation channel activated by calcium and proton and is involved in hedgehog signaling, intestinal development, and sour tasting. How TRPP3 channel function is regulated remains poorly understood. By N-terminal truncation mutations, electrophysiology, and Xenopus oocyte expression, we first identified fragment Asp-21-Ser-42 to be functionally important. We then found that deletion mutant ⌬1-36 (TRPP3 missing fragment Met-1-Arg-36) has a similar function as wild-type TRPP3, whereas ⌬1-38 is functionally dead, suggesting the importance of Val-37 or Cys-38. Further studies found that Cys-38, but not Val-37, is functionally critical. Cys-38 is a predicted site of palmitoylation, and indeed TRPP3 channel activity was inhibited by palmitoylation inhibitor 2-bromopalmitate and rescued by palmitoylation substrate palmitic acid. The TRPP3 N terminus (TRPP3NT, Met-1-Leu-95) localized along the plasma membrane of HEK293 cells but stayed in the cytoplasm with 2-bromopalmitate treatment or C38A mutation, indicating that TRPP3NT anchors to the surface membrane through palmitoylation at Cys-38. By acyl-biotin exchange assays, we showed that TRPP3, but not mutant C38A, is indeed palmitoylated. When putative phosphorylation sites near Cys-38 were mutated to Asp or Glu to mimic phosphorylation, only T39D and T39E reduced TRPP3 function. Furthermore, TRPP3NT displayed double bands in which the upper band was abolished by phosphatase treatment or T39A mutation. However, palmitoylation at Cys-38 and phosphorylation at Thr-39 independently regulated TRPP3 channel function, in contrast to previous reports about correlated palmitoylation with a proximate phosphorylation. Palmitoylation at Cys-38 represents a novel mechanism of functional regulation for TRPP3.

show abstract

The “Sweet” Side of Ion Channels

Łaźniewska

Weiss

2014

Reviews of Physiology, Biochemistry and Pharmacology

View full text Add to dashboard Cite

Ion channels play a crucial role in cell functioning, contributing to transmembrane potential and participating in cell signalling and homeostasis. To fulfil highly specialised functions, cells have developed various mechanisms to regulate channel expression and activity at particular subcellular loci, and alteration of ion channel regulation can lead to serious disorders. Glycosylation, one of the most common forms of co- and post-translational protein modification, is rapidly emerging as a fundamental mechanism not only controlling the proper folding of nascent channels but also their subcellular localisation, gating and function. Moreover, studies on various channel subtypes have revealed that glycosylation represents an important determinant by which other signalling pathways modulate channel activity. The discovery of detailed mechanisms of regulation of ion channels by glycosylation provides new insights in the physiology of ion channels and may allow developing new pharmaceutics for the treatment of ion channel-related disorders.

show abstract

Ion channel regulation by protein S-acylation

Cited by 59 publications

References 136 publications

Dynamic cycling of t-SNARE acylation regulates platelet exocytosis

Dynamic cycling of t-SNARE acylation regulates platelet exocytosis

Regulation of TRPP3 Channel Function by N-terminal Domain Palmitoylation and Phosphorylation

The “Sweet” Side of Ion Channels

Contact Info

Product

Resources

About