Phosphoinositide dynamics in the postsynaptic membrane compartment: Mechanisms and experimental approach

Leitner, Michael G.; Halaszovich, Christian R.; Ivanova, O. Yu.; Oliver, Dominik

doi:10.1016/j.ejcb.2015.06.003

Cited by 11 publications

(19 citation statements)

References 194 publications

(361 reference statements)

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“…In this model, reggies appear to create or demarcate membrane domains of specific lipid composition, probably like EHD1 and SNX4, which are residents of the same recycling compartment in Hela and A431 cells as the reggies and which are associated with phosphatidylinositol-4-phosphate and phosphatidylinositol-4,5-bisphosphate (PIP2) (Jovic et al, 2009;Cullen, 2011;Solis et al, 2013). Different phospho-inositides are implied in (post)synaptic plasticity and AMPA receptor (GluA) recycling (Leitner et al, 2015). Conceivably then, reggies might organize microdomains with specific lipids and lipid modified proteins and promote their vesicular transport and delivery to specific regions such as the PSD.…”

Section: Reggies In Raftsmentioning

confidence: 99%

Reggie-1 and reggie-2 (flotillins) participate in Rab11a-dependent cargo trafficking, spine synapse formation and LTP-related AMPA receptor (GluA1) surface exposure in mouse hippocampal neurons

Bodrikov

Pauschert

Kochlamazashvili

et al. 2017

Experimental Neurology

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a b s t r a c tReggie-1 and -2 (flotillins) reside at recycling vesicles and promote jointly with Rab11a the targeted delivery of cargo. Recycling is essential for synapse formation suggesting that reggies and Rab11a may regulate the development of spine synapses. Recycling vesicles provide cargo for dendritic growth and recycle surface glutamate receptors (AMPAR, GluA) for long-term potentiation (LTP) induced surface exposure. Here, we show reduced number of spine synapses and impairment of an in vitro correlate of LTP in hippocampal neurons from reggie-1 k.o. (Flot2−/−) mice maturating in culture. These defects apparently result from reduced trafficking of PSD-95 revealed by live imaging of 10 div reggie-1 k.o. (Flot2 −/−) neurons and likely impairs co-transport of cargo destined for spines: N-cadherin and the glutamate receptors GluA1 and GluN1. Impaired cargo trafficking and fewer synapses also emerged in reggie-1 siRNA, reggie-2 siRNA, and reggie-1 and -2 siRNA-treated neurons and was in siRNA and k.o. neurons rescued by reggie-1-EGFP and CA-Rab11a-EGFP. While correlative expressional changes of specific synapse proteins were observed in reggie-1 k.o. (Flot2−/−) brains in vivo, this did not occur in neurons maturating in vitro. Our work suggests that reggie-1 and reggie-2 function at Rab11a recycling containers in the transport of PSD-95, N-cadherin, GluA1 and GluN1, and promote (together with significant signaling molecules) spine-directed trafficking, spine synapse formation and the in vitro correlate of LTP.

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Section: Reggies In Raftsmentioning

confidence: 99%

Reggie-1 and reggie-2 (flotillins) participate in Rab11a-dependent cargo trafficking, spine synapse formation and LTP-related AMPA receptor (GluA1) surface exposure in mouse hippocampal neurons

Bodrikov

Pauschert

Kochlamazashvili

et al. 2017

Experimental Neurology

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“…For in situ CID, cells need to express two components, membrane-targeted proteins and PIP 2 -specific phosphatases, that allow rapid metabolism of PIP 2 within the plasma membrane 22 . Although this CID system has been used in several cell types, it would be difficult to introduce two components at an equimolar ratio into individual neurons and extend this system to brain slices and even intact animals 24, 25 . Thus, we designed a new viral construct using the 2 A peptide sequence from the insect Thosea asigna virus (T2A) to link the two components 26 : The enhanced cyan fluorescent protein (eCFP) or the enhanced green fluorescent protein (eGFP) sequence fused to the N-terminus of FKBP-Inp54p (FKBP-Inp54p) was linked to Lyn 11 -FRB (LDR), a membrane-anchored FRB, via a T2A-linked sequence (LDR-T2A-Inp54p) (Fig.…”

Section: Resultsmentioning

confidence: 99%

“…Ectopic expression of the enzymes does not allow a determination of the timeframe during which PIP 2 can exert its action on each stage of synaptic plasticity. Furthermore, pharmacological modulation of PIP 2 -modifying enzymes has the caveats of potential off-target effects and diffusion time, particularly problematic in brain tissues 25 .…”

Section: Discussionmentioning

confidence: 99%

Identification of postsynaptic phosphatidylinositol-4,5-bisphosphate (PIP2) roles for synaptic plasticity using chemically induced dimerization

Kim

Jeong

et al. 2017

Sci Rep

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Phosphatidylinositol-4,5-bisphosphate (PIP2), one of the key phospholipids, directly interacts with several membrane and cytosolic proteins at neuronal plasma membranes, leading to changes in neuronal properties including the feature and surface expression of ionotropic receptors. Although PIP2 is also concentrated at the dendritic spines, little is known about the direct physiological functions of PIP2 at postsynaptic as opposed to presynaptic sites. Most previous studies used genetic and pharmacological methods to modulate enzymes that alter PIP2 levels, making it difficult to delineate time- or region-specific roles of PIP2. We used chemically-induced dimerization to translocate inositol polyphosphate 5-phosphatase (Inp54p) to plasma membranes in the presence of rapamycin. Upon redistribution of Inp54p, long-term depression (LTD) induced by low-frequency stimulation was blocked in the mouse hippocampal CA3-CA1 pathway, but the catalytically-dead mutant did not affect LTD induction. Collectively, PIP2 is critically required for induction of LTD whereas translocation of Inp54p to plasma membranes has no effect on the intrinsic properties of the neurons, basal synaptic transmission, long-term potentiation or expression of LTD.

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“…; Leitner et al . ). Ion‐channel phosphorylation and PIP 2 availability are governed by protein kinases and phospholipases, respectively, whose latter activities are controlled by G protein‐coupled receptors (GPCRs).…”

Section: Introductionmentioning

confidence: 97%

“…Protein phosphorylation of ion channels is vital for neuronal function (Walaas & Greengard, 1991). It has recently become clear that ion-channel function also relies on the availability of phosphatidylinositol 4,5-bisphosphate (PIP 2 ; Gamper & Shapiro, 2007), one of the most common phosphoinositides in the plasma membrane (Falkenburger et al 2010;Leitner et al 2015). Ion-channel phosphorylation and PIP 2 availability are governed by protein kinases and phospholipases, respectively, whose latter activities are controlled by G protein-coupled receptors (GPCRs).…”

Section: Introductionmentioning

confidence: 99%

Phosphorylation regulates the sensitivity of voltage‐gated Kv7.2 channels towards phosphatidylinositol‐4,5‐bisphosphate

Salzer

Erdem

Chen

et al. 2016

The Journal of Physiology

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Key points Phosphatidylinositol‐4,5‐bisphosphate (PIP2) is a key regulator of many membrane proteins, including voltage‐gated Kv7.2 channels.In this study, we identified the residues in five phosphorylation sites and their corresponding protein kinases, the former being clustered within one of four putative PIP2‐binding domains in Kv7.2.Dephosphorylation of these residues reduced the sensitivity of Kv7.2 channels towards PIP2.Dephosphorylation of Kv7.2 affected channel inhibition via M1 muscarinic receptors, but not via bradykinin receptors.Our data indicated that phosphorylation of the Kv7.2 channel was necessary to maintain its low affinity for PIP2, thereby ensuring the tight regulation of the channel via G protein‐coupled receptors. AbstractThe function of numerous ion channels is tightly controlled by G protein‐coupled receptors (GPCRs). The underlying signalling mechanisms may involve phosphorylation of channel proteins and participation of phosphatidylinositol‐4,5‐bisphosphate (PIP2). Although the roles of both mechanisms have been investigated extensively, thus far only little has been reported on their interaction in channel modulation. GPCRs govern Kv7 channels, the latter playing a major role in the regulation of neuronal excitability by determining the levels of PIP2 and through phosphorylation. Using liquid chromatography‐coupled mass spectrometry for Kv7.2 immunoprecipitates of rat brain membranes and transfected cells, we mapped a cluster of five phosphorylation sites in one of the PIP2‐binding domains. To evaluate the effect of phosphorylation on PIP2‐mediated Kv7.2 channel regulation, a quintuple alanine mutant of these serines (S427/S436/S438/S446/S455; A5 mutant) was generated to mimic the dephosphorylated state. Currents passing through these mutated channels were less sensitive towards PIP2 depletion via the voltage‐sensitive phosphatase Dr‐VSP than were wild‐type channels. In vitro phosphorylation assays with the purified C‐terminus of Kv7.2 revealed that CDK5, p38 MAPK, CaMKIIα and PKA were able to phosphorylate the five serines. Inhibition of these protein kinases reduced the sensitivity of wild‐type but not mutant Kv7.2 channels towards PIP2 depletion via Dr‐VSP. In superior cervical ganglion neurons, the protein kinase inhibitors attenuated Kv7 current regulation via M1 receptors, but left unaltered the control by B2 receptors. Our results revealed that the phosphorylation status of serines located within a putative PIP2‐binding domain determined the phospholipid sensitivity of Kv7.2 channels and supported GPCR‐mediated channel regulation.

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Phosphoinositide dynamics in the postsynaptic membrane compartment: Mechanisms and experimental approach

Cited by 11 publications

References 194 publications

Reggie-1 and reggie-2 (flotillins) participate in Rab11a-dependent cargo trafficking, spine synapse formation and LTP-related AMPA receptor (GluA1) surface exposure in mouse hippocampal neurons

Reggie-1 and reggie-2 (flotillins) participate in Rab11a-dependent cargo trafficking, spine synapse formation and LTP-related AMPA receptor (GluA1) surface exposure in mouse hippocampal neurons

Identification of postsynaptic phosphatidylinositol-4,5-bisphosphate (PIP2) roles for synaptic plasticity using chemically induced dimerization

Phosphorylation regulates the sensitivity of voltage‐gated Kv7.2 channels towards phosphatidylinositol‐4,5‐bisphosphate

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