A distinct pool of phosphatidylinositol 4,5-bisphosphate in caveolae revealed by a nanoscale labeling technique

Fujita, Akikazu; Cheng, Jinglei; Tauchi-Sato, Kumi; Takenawa, Tadaomi; Fujimoto, Toyoshi

doi:10.1073/pnas.0900216106

Cited by 178 publications

(182 citation statements)

References 55 publications

(56 reference statements)

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“…Together these observations suggest that PtdSer may play a critical role in the formation and stabilization of caveolae. Consistent with this notion, electron microscopic (EM) studies revealed an enrichment of a PtdSerbinding probe in caveolae (22,23).…”

Section: Edited By Dennis R Voelkersupporting

confidence: 58%

Phosphatidylserine dictates the assembly and dynamics of caveolae in the plasma membrane

Hirama

Das

Yang

et al. 2017

Journal of Biological Chemistry

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Edited by Dennis R. VoelkerCaveolae are bulb-shaped nanodomains of the plasma membrane that are enriched in cholesterol and sphingolipids. They have many physiological functions, including endocytic transport, mechanosensing, and regulation of membrane and lipid transport. Caveola formation relies on integral membrane proteins termed caveolins (Cavs) and the cavin family of peripheral proteins. Both protein families bind anionic phospholipids, but the precise roles of these lipids are unknown. Here, we studied the effects of phosphatidylserine (PtdSer), phosphatidylinositol 4-phosphate (PtdIns4P), and phosphatidylinositol 4,5-bisphosphate (PtdIns(4,5)P 2 ) on caveolar formation and dynamics. Using live-cell, single-particle tracking of GFP-labeled Cav1 and ultrastructural analyses, we compared the effect of PtdSer disruption or phosphoinositide depletion with caveola disassembly caused by cavin1 loss. We found that PtdSer plays a crucial role in both caveola formation and stability. Sequestration or depletion of PtdSer decreased the number of detectable Cav1-GFP puncta and the number of caveolae visualized by electron microscopy. Under PtdSer-limiting conditions, the co-localization of Cav1 and cavin1 was diminished, and cavin1 degradation was increased. Using rapamycin-recruitable phosphatases, we also found that the acute depletion of PtdIns4P and PtdIns (4,5)P 2 has minimal impact on caveola assembly but results in decreased lateral confinement. Finally, we show in a model of phospholipid scrambling, a feature of apoptotic cells, that caveola stability is acutely affected by the scrambling. We conclude that the predominant plasmalemmal anionic lipid PtdSer is essential for proper Cav clustering, caveola formation, and caveola dynamics and that membrane scrambling can perturb caveolar stability.

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Section: Edited By Dennis R Voelkersupporting

confidence: 58%

Phosphatidylserine dictates the assembly and dynamics of caveolae in the plasma membrane

Hirama

Das

Yang

et al. 2017

Journal of Biological Chemistry

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“…Considering that IP 3 is the head group of PI(4,5)P 2 , IP 3 may compete with PI(4,5)P 2 for ARD binding 33 . Consistent with this notion, 4a-PDD-evoked currents through TRPV4 were suppressed by the addition of the longer acyl chains of PI(4,5)P 2 (diC8-PI(4,5)P 2 and diC16-PI(4,5)P 2 ), but were augmented by the addition of the shorter acyl chains of PI(4,5)P 2 (diC4-PI(4,5)P 2 ) ( Supplementary Fig.…”

Section: Resultsmentioning

confidence: 99%

TRPV4 channel activity is modulated by direct interaction of the ankyrin domain to PI(4,5)P2

et al. 2014

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Mutations in the ankyrin repeat domain (ARD) of TRPV4 are responsible for several channelopathies, including Charcot-Marie-Tooth disease type 2C and congenital distal and scapuloperoneal spinal muscular atrophy. However, the molecular pathogenesis mediated by these mutations remains elusive, mainly due to limited understanding of the TRPV4 ARD function. Here we show that phosphoinositide binding to the TRPV4 ARD leads to suppression of the channel activity. Among the phosphoinositides, phosphatidylinositol-4,5-bisphosphate (PI(4,5)P 2 ) most potently binds to the TRPV4 ARD. The crystal structure of the TRPV4 ARD in complex with inositol-1,4,5-trisphosphate, the head-group of PI(4,5)P 2 , and the molecular-dynamics simulations revealed the PI(4,5)P 2 -binding amino-acid residues. The TRPV4 channel activities were increased by titration or hydrolysis of membrane PI(4,5)P 2 . Notably, disease-associated TRPV4 mutations that cause a gain-of-function phenotype abolished PI(4,5)P 2 binding and PI(4,5)P 2 sensitivity. These findings identify TRPV4 ARD as a lipid-binding domain in which interactions with PI(4,5)P 2 normalize the channel activity in TRPV4.

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“…A likely explanation for these differences is that the various PI(4,5)P 2 sensors (PH domains, antibodies, KCNQ2/3 channels, and isotope labeling) have different sensitivities and different nonlinearities and may not monitor identical pools of PM PI(4,5)P 2 . There is also some evidence for signaling microdomains (55)(56)(57) and independent pools of PI(4,5)P 2 (58,59) in nanodomains (60,61), possibilities that remain controversial (62).…”

Section: Discussionmentioning

confidence: 99%

Golgi and plasma membrane pools of PI(4)P contribute to plasma membrane PI(4,5)P ₂ and maintenance of KCNQ2/3 ion channel current

Dickson

Jensen

Hille

2014

Proc. Natl. Acad. Sci. U.S.A.

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Plasma membrane (PM) phosphatidylinositol 4,5-bisphosphate [PI(4,5)P 2 ] regulates the activity of many ion channels and other membrane-associated proteins. To determine precursor sources of the PM PI(4,5)P 2 pool in tsA-201 cells, we monitored KCNQ2/3 channel currents and translocation of PH PLCδ1 domains as real-time indicators of PM PI(4,5)P 2 , and translocation of PH OSH2×2 , and PH OSH1 domains as indicators of PM and Golgi phosphatidylinositol 4-phosphate [PI(4)P], respectively. We selectively depleted PI(4)P pools at the PM, Golgi, or both using the rapamycin-recruitable lipid 4-phosphatases. Depleting PI(4)P at the PM with a recruitable 4-phosphatase (Sac1) results in a decrease of PI(4,5)P 2 measured by electrical or optical indicators. Depleting PI(4)P at the Golgi with the 4-phosphatase or disrupting membrane-transporting motors induces a decline in PM PI(4,5)P 2 . Depleting PI(4)P simultaneously at both the Golgi and the PM induces a larger decrease of PI(4,5)P 2 . The decline of PI(4,5)P 2 following 4-phosphatase recruitment takes 1-2 min. Recruiting the endoplasmic reticulum (ER) toward the Golgi membranes mimics the effects of depleting PI(4)P at the Golgi, apparently due to the trans actions of endogenous ER Sac1. Thus, maintenance of the PM pool of PI(4,5)P 2 appears to depend on precursor pools of PI(4)P both in the PM and in the Golgi. The decrease in PM PI(4,5)P 2 when Sac1 is recruited to the Golgi suggests that the Golgi contribution is ongoing and that PI (4,5)P 2 production may be coupled to important cell biological processes such as membrane trafficking or lipid transfer activity.phosphoinositides | wortmannin | pleckstrin homology domain T his paper concerns the dynamics of cellular pools of phosphoinositides, a family of phospholipids located on the cytoplasmic leaflet of cellular membranes, that maintain cell structure, cell motility, membrane identity, and membrane trafficking; they also play key roles in signal transduction (1). Phosphatidylinositol (PI) can be phosphorylated at three positions to generate seven additional species. The subcellular localization of each phosphoinositide is tightly governed by the concurrent presence of lipid kinases and lipid phosphatases (2, 3), giving each membrane within the cell a unique and dynamic phosphoinositide signature (4). Phosphatidylinositol 4,5-bisphosphate [PI(4,5)P 2 ] is localized to the inner leaflet of the plasma membrane (PM) and is the major substrate of phospholipase C (PLC). As a consequence, PI(4,5)P 2 levels are dynamically regulated by G q -coupled receptors activating PLC. The activity of lipid kinases and phosphatases also can be modulated by signaling; for example, a PI 4-kinase, when associated with neuronal calcium sensor-1, is accelerated in response to elevated calcium that occurs with PI(4,5)P 2 cleavage (5). In addition, transient apposition between organelles can alter phosphoinositide levels by presenting membrane-bound phosphatases in trans. For example, the endoplasmic reticulum (ER) can make contacts with the...

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A distinct pool of phosphatidylinositol 4,5-bisphosphate in caveolae revealed by a nanoscale labeling technique

Cited by 178 publications

References 55 publications

Phosphatidylserine dictates the assembly and dynamics of caveolae in the plasma membrane

Phosphatidylserine dictates the assembly and dynamics of caveolae in the plasma membrane

TRPV4 channel activity is modulated by direct interaction of the ankyrin domain to PI(4,5)P2

Golgi and plasma membrane pools of PI(4)P contribute to plasma membrane PI(4,5)P ₂ and maintenance of KCNQ2/3 ion channel current

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A distinct pool of phosphatidylinositol 4,5-bisphosphate in caveolae revealed by a nanoscale labeling technique

Cited by 178 publications

References 55 publications

Phosphatidylserine dictates the assembly and dynamics of caveolae in the plasma membrane

Phosphatidylserine dictates the assembly and dynamics of caveolae in the plasma membrane

TRPV4 channel activity is modulated by direct interaction of the ankyrin domain to PI(4,5)P2

Golgi and plasma membrane pools of PI(4)P contribute to plasma membrane PI(4,5)P 2 and maintenance of KCNQ2/3 ion channel current

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Golgi and plasma membrane pools of PI(4)P contribute to plasma membrane PI(4,5)P ₂ and maintenance of KCNQ2/3 ion channel current