Detection and manipulation of phosphoinositides

Abstract

Phosphoinositides (PIs) are minor components of cell membranes, but play key roles in cell function. Recent refinements in techniques for their detection, together with imaging methods to study their distribution and changes, have greatly facilitated the study of these lipids. Such methods have been complemented by the parallel development of techniques for the acute manipulation of their levels, which in turn allow bypassing the long-term adaptive changes implicit in genetic perturbations. Collectively, these advancements have helped elucidate the role of PIs in physiology and the impact of the dysfunction of their metabolism in disease. Combining methods for detection and manipulation enables the identification of specific roles played by each of the PIs and may eventually lead to the complete deconstruction of the PI signaling network. Here, we review current techniques used for the study and manipulation of cellular PIs and also discuss advantages and disadvantages associated with the various methods. This article is part of a Special Issue entitled Phosphoinositides.

A phosphoinositide conversion mechanism for exit from endosomes

“…In order to test whether MTM1-mediated removal of endosomal PI(3)P is a prerequisite for the dissociation of PI(3)P-effector proteins, and thus for successful endosomal recycling, we next investigated the effects of manipulating endosomal PI(3)P levels, synthesis, turn-over or localization in MTM1-depleted cells (Idevall-Hagren and De Camilli 2015).…”

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

“…PLC, PI kinases, and PI phosphatases. Unfortunately, the pharmacology of phosphoinositide metabolism is poorly developed, with the notable exception of subtype-specific PI-3 kinase inhibitors, which have been reviewed in detail elsewhere (Fruman and Rommel, 2014;Idevall-Hagren and De Camilli, 2015). Here, we briefly review some compounds commonly used and point out a few issues that should be considered.…”

“…It should be considered, however, that long-term changes in PI synthesis and abundance may be subject to compensatory mechanisms. Moreover, due to the multitude of fundamental cellular processes affected by PIs, long-term changes may lead to multiple alterations in cell biology that can complicate the interpretation of effects on the (postsynaptic) mechanism of interest Idevall-Hagren and De Camilli, 2015). To circumvent these potential pitfalls of pharmacological and long-term manipulation, several innovative techniques have been developed recently, which allow for an unprecedented level of temporal and even spatial control of PI concentrations (Idevall-Hagren and De Camilli, 2015).…”

Optogenetic approaches for dissecting neuromodulation and GPCR signaling in neural circuits

“…Additional genetic engineering would be required to enable cells to synthesize PCB [60]. Phytochromes have been used to generate optogenetic tools for the regulation of phosphoinositides and ERK [61,62]. It is likely that future iterations of phytochrome domains will begin to be used in cultured neurons and in brain tissue as they become refined and more well accepted.…”