H2020Индивидуална стипендия2021–2023

MEMTOR · Understanding mechanisms of membrane tension loss and recovery using small-molecule tools

„Хоризонт 2020“ — Действия „Мария Склодовска-Кюри“

Период: 2021-05-01 → 2023-04-30
Финансиране от ЕС: 203 149 €
Участници: 1
Схема: MSCA-IF

Линиите свързват координатора с партньорите.

Накратко на български

Механизмите за регулиране на напрежението в клетъчната мембрана се анализират чрез действието на малки молекули като palmitoylcarnitine. Разбирането на тези процеси помага при изследването на метаболитния синдром, невродегенерацията и разпространението на раковия тумор.

Този кратък обзор е генериран от изкуствен интелект

Кратко обяснение, генерирано от езиков модел по текста на CORDIS. Оригиналът е по-долу.

Резултати накратко

Understanding mechanisms of membrane tension loss and recovery using small-molecule tools

The plasma membrane is a network of lipids and proteins that serves as a physical barrier between the external environment and the interior of the cell. The maintenance of plasma membrane tension homeostasis is vitally important to prevent cancer metastasis, neurodegeneration, and metabolic syndrome. However, the study of this important process has lagged due to a lack of tools to measure and manipulate the behavior of lipids in the context of cellular membranes. Starting from the observation that a small molecule, palmitoylcarnitine (PalmC), discovered in a screen in our lab, is able to induce membrane tension loss and plasma membrane invaginations, and inhibit the activity of the signaling complex that serves as a master regulator of membrane tension (TORC2), our aim was to characterize the mechanism by which PalmC alters plasma membrane tension (Aim 1). Our studies have revealed that PalmC, in addition to other small amphipathic molecules, acts directly on the plasma membrane and achieves its effects in a sterol-dependent manner. During the course of this work, we also made a serendipitous discovery while purifying native TORC2 protein from yeast cells (Aim 2). We isolated a membrane-bound structure of the eisosome, a unique plasma membrane microdomain found in yeast which senses membrane stress and initiates signaling to TORC2. These isolated native eisosomes, scaffolded by the BAR-domain proteins Pil1 and Lsp1, were bound to a plasma membrane bilayer (See figure). By solving cryoEM structures of these native eisosomes, we were able to observe that the bound membrane has a remarkably well-organized structure with signatures of specific lipid species discernable within the membrane bilayer. These native eisosomes and their high-resolution structures have provided us a unique window into the organization of the lipids within a membrane microdomain.

Текст от CORDIS, на английски · Данни: CORDIS, © Европейски съюз

Цел на проекта

Maintenance of membrane tension at the plasma membrane (PM) is an important yet understudied aspect of cellular homeostasis. Dysregulated membrane tension homeostasis has roles in cancer, neurodegeneration, and metabolic syndrome but its study has been limited by a lack of tools to measure and manipulate it. The Target of Rapamycin Complex 2 (TORC2), an important signaling hub regulating cell growth, has an unexpected role in maintaining PM tension homeostasis. A screen for TORC2-specific inhibitors identified the lipophilic molecule palmitoylcarnitine (PalmC) which induces a reversible loss in PM tension. It is currently unknown how PalmC is able to induce this tension loss, but understanding both its mode-of-action and how cells are able to recover from its effects are important for its development as a potential membrane-targeting drug. In this proposal, we aim to reveal key proteins involved in the effects of PalmC (Aim 1). We expect that a specific plasma membrane-localized transporter will mediate its uptake. Both by identifying this protein and solving its structure in a native-like lipidic environment and/or in complex with PalmC, we hope to reveal new insights into how PalmC might be tailored for therapeutic potential. We will also investigate the recovery process post-PalmC treatment, starting from the observation that the TORC2-activating protein Slm1 co-localizes with TORC2 and forms very large clusters at sites of PalmC-induced membrane invaginations (Aim 2). Previous observations of TORC1 regulation suggest that clustering is correlated with the formation of ordered polymers. To investigate whether this is a conserved mechanism of regulation, we will attempt to isolate a Slm1-TORC2 superstructure and determine its structure using cryoEM with the expectation that structural details about the interactions between these proteins within the superstructure will reveal mechanistic insights into the regulation of TORC2, as well as membrane tension.

Оригинален текст от CORDIS (на английски).

Участници

UNIVERSITE DE GENEVE · GeneveКоординаторШвейцария