Browse
Submit Data
Databases
API
Help

Dataset Information

17 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Activation Mechanisms of the VPS34 Complexes.

ABSTRACT: Phosphatidylinositol-3-phosphate (PtdIns(3)P) is essential for cell survival, and its intracellular synthesis is spatially and temporally regulated. It has major roles in two distinctive cellular pathways, namely, the autophagy and endocytic pathways. PtdIns(3)P is synthesized from phosphatidylinositol (PtdIns) by PIK3C3C/VPS34 in mammals or Vps34 in yeast. Pathway-specific VPS34/Vps34 activity is the consequence of the enzyme being incorporated into two mutually exclusive complexes: complex I for autophagy, composed of VPS34/Vps34-Vps15/Vps15-Beclin 1/Vps30-ATG14L/Atg14 (mammals/yeast), and complex II for endocytic pathways, in which ATG14L/Atg14 is replaced with UVRAG/Vps38 (mammals/yeast). Because of its involvement in autophagy, defects in which are closely associated with human diseases such as cancer and neurodegenerative diseases, developing highly selective drugs that target specific VPS34/Vps34 complexes is an essential goal in the autophagy field. Recent studies on the activation mechanisms of VPS34/Vps34 complexes have revealed that a variety of factors, including conformational changes, lipid physicochemical parameters, upstream regulators, and downstream effectors, greatly influence the activity of these complexes. This review summarizes and highlights each of these influences as well as clarifying key questions remaining in the field and outlining future perspectives.

SUBMITTER: Ohashi Y

PROVIDER: S-EPMC8624279 | biostudies-literature |

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Similar Datasets

VPS34 complexes from a structural perspective.

Project description:VPS34 phosphorylates phosphatidylinositol to produce PtdIns3P and is the progenitor of the phosphoinositide 3-kinase (PI3K) family. VPS34 has a simpler domain organization than class I PI3Ks, which belies the complexity of its quaternary organization, with the enzyme always functioning within larger assemblies. PtdIns3P recruits specific recognition modules that are common in protein-sorting pathways, such as autophagy and endocytic sorting. It is best characterized in two heterotetramers, complexes I and II. Complex I is composed of VPS34, VPS15, Beclin 1, and autophagy-related gene (ATG)14L, whereas complex II replaces ATG14L with UVRAG. Because VPS34 can form a component of several distinct complexes, it enables independent regulation of various pathways that are controlled by PtdIns3P. Complexes I and II are critical for early events in autophagy and endocytic sorting, respectively. Autophagy has a complex association with cancer. In early stages, it inhibits tumorigenesis, but in later stages, it acts as a survival factor for tumors. Recently, various disease-associated somatic mutations were found in genes encoding complex I and II subunits. Lipid kinase activities of the complexes are also influenced by posttranslational modifications (PTMs). Mapping PTMs and somatic mutations on three-dimensional models of the complexes suggests mechanisms for how these affect VPS34 activity.

| S-EPMC6358306 | biostudies-literature

Membrane characteristics tune activities of endosomal and autophagic human VPS34 complexes.

Project description:The lipid kinase VPS34 orchestrates diverse processes, including autophagy, endocytic sorting, phagocytosis, anabolic responses and cell division. VPS34 forms various complexes that help adapt it to specific pathways, with complexes I and II being the most prominent ones. We found that physicochemical properties of membranes strongly modulate VPS34 activity. Greater unsaturation of both substrate and non-substrate lipids, negative charge and curvature activate VPS34 complexes, adapting them to their cellular compartments. Hydrogen/deuterium exchange mass spectrometry (HDX-MS) of complexes I and II on membranes elucidated structural determinants that enable them to bind membranes. Among these are the Barkor/ATG14L autophagosome targeting sequence (BATS), which makes autophagy-specific complex I more active than the endocytic complex II, and the Beclin1 BARA domain. Interestingly, even though Beclin1 BARA is common to both complexes, its membrane-interacting loops are critical for complex II, but have only a minor role for complex I.

| S-EPMC7326497 | biostudies-literature

Regulation of PIK3C3/VPS34 complexes by MTOR in nutrient stress-induced autophagy.

Project description:Autophagy is a cellular defense response to stress conditions, such as nutrient starvation. The type III phosphatidylinositol (PtdIns) 3-kinase, whose catalytic subunit is PIK3C3/VPS34, plays a critical role in intracellular membrane trafficking and autophagy induction. PIK3C3 forms multiple complexes and the ATG14-containing PIK3C3 is specifically involved in autophagy induction. Mechanistic target of rapamycin (MTOR) complex 1, MTORC1, is a key cellular nutrient sensor and integrator to stimulate anabolism and inhibit catabolism. Inactivation of TORC1 by nutrient starvation plays a critical role in autophagy induction. In this report we demonstrated that MTORC1 inactivation is critical for the activation of the autophagy-specific (ATG14-containing) PIK3C3 kinase, whereas it has no effect on ATG14-free PIK3C3 complexes. MTORC1 inhibits the PtdIns 3-kinase activity of ATG14-containing PIK3C3 by phosphorylating ATG14, which is required for PIK3C3 inhibition by MTORC1 both in vitro and in vivo. Our data suggest a mechanistic link between amino acid starvation and autophagy induction via the direct activation of the autophagy-specific PIK3C3 kinase.

| S-EPMC4028342 | biostudies-literature

Two mammalian MOF complexes regulate transcription activation by distinct mechanisms.

Project description:In mammals, MYST family histone acetyltransferase MOF plays important roles in transcription activation by acetylating histone H4 on K16, a prevalent mark associated with chromatin decondensation, and transcription factor p53 on K120, which is important for activation of proapoptotic genes. However, little is known about MOF regulation in higher eukaryotes. Here, we report that the acetyltransferase activity of MOF is tightly regulated in two different but evolutionarily conserved complexes, MSL and MOF-MSL1v1. Importantly, we demonstrate that while the two MOF complexes have indistinguishable activity on histone H4 K16, they differ dramatically in acetylating nonhistone substrate p53. We further demonstrate that MOF-MSL1v1 is specifically required for optimal transcription activation of p53 target genes both in vitro and in vivo. Our results support a model that these two MOF complexes regulate distinct stages of transcription activation in cooperation with other histone modifying activities.

| S-EPMC2768600 | biostudies-literature

Differential regulation of distinct Vps34 complexes by AMPK in nutrient stress and autophagy.

Project description:Autophagy is a stress response protecting cells from unfavorable conditions, such as nutrient starvation. The class III phosphatidylinositol-3 kinase, Vps34, forms multiple complexes and regulates both intracellular vesicle trafficking and autophagy induction. Here, we show that AMPK plays a key role in regulating different Vps34 complexes. AMPK inhibits the nonautophagy Vps34 complex by phosphorylating T163/S165 in Vps34 and therefore suppresses overall PI(3)P production and protects cells from starvation. In parallel, AMPK activates the proautophagy Vps34 complex by phosphorylating S91/S94 in Beclin1 to induce autophagy. Atg14L, an autophagy-essential gene present only in the proautophagy Vps34 complex, inhibits Vps34 phosphorylation but increases Beclin1 phosphorylation by AMPK. As such, Atg14L dictates the differential regulation (either inhibition or activation) of different Vps34 complexes in response to glucose starvation. Our study reveals an intricate molecular regulation of Vps34 complexes by AMPK in nutrient stress response and autophagy.

| S-EPMC3587159 | biostudies-literature

Tailored Parameterization of the LIE Method for Calculating the Binding Free Energy of Vps34–Inhibitor Complexes

Project description:Vps34 is the only

| S-EPMC8582068 | biostudies-literature

VPS34 regulates RAB7 activation and Retromer localization to autophagosomes and mitophagy in oocytes

Project description:To investigate the role of Vps34 during oocyte development, we crossed female Vps34f/f mice with Gdf9-Cre and Zp3-Cre male transgenic mice for Cre recombinase specifically in oocytes at either primordial or early growing stages. Our results revealed that Vps34 plays a key role in oocyte cytoplasmic maturation. In order to reveal the changes in oocyte transcriptome level caused by Vps34 deletion, we conducted transcriptome sequencing on oocytes at GV stage, MII stage and 2cell embryo of ZcKO, and analyzed the changes in transcripts at these three stages. Transcriptome sequencing results showed that the oocytes and 2cell embryos of ZcKO were enriched with a large number of transcription and transport-related differential genes, and the 2cell stage had the most differential genes, which was the key period for the occurrence of major ZGA. Further analysis of transcription-related genes revealed that the enriched major ZGA genes were all down-regulated in 2cell of ZcKO mice. In addition, differential genes involved in autophagy were enriched in ZcKO 2cell, with HPG abnormally increased. Autophagy is the main degradation pathways of maternal proteins in early embryonic development, and degradation of maternal proteins is necessary for the normal process of ZGA, which occurs prior to major ZGA and even during oocyte maturation, when defects appear to be irremediable later. These results suggest that Vps34 deletion leads to degradation inhibition of maternal factors and impaired major ZGA, leading to embryonic development arrest.

2023-09-01 | GSE216465 | GEO

TRPML1 links lysosomal calcium to autophagosome biogenesis through the activation of the CaMKKβ/VPS34 pathway.

Project description:The lysosomal calcium channel TRPML1, whose mutations cause the lysosomal storage disorder (LSD) mucolipidosis type IV (MLIV), contributes to upregulate autophagic genes by inducing the nuclear translocation of the transcription factor EB (TFEB). Here we show that TRPML1 activation also induces autophagic vesicle (AV) biogenesis through the generation of phosphatidylinositol 3-phosphate (PI3P) and the recruitment of essential PI3P-binding proteins to the nascent phagophore in a TFEB-independent manner. Thus, TRPML1 activation of phagophore formation requires the calcium-dependent kinase CaMKKβ and AMPK, which increase the activation of ULK1 and VPS34 autophagic protein complexes. Consistently, cells from MLIV patients show a reduced recruitment of PI3P-binding proteins to the phagophore during autophagy induction, suggesting that altered AV biogenesis is part of the pathological features of this disease. Together, we show that TRPML1 is a multistep regulator of autophagy that may be targeted for therapeutic purposes to treat LSDs and other autophagic disorders.

| S-EPMC6904751 | biostudies-literature

Structures of signaling complexes of lipid receptors S1PR1 and S1PR5 reveal mechanisms of activation and drug recognition.

Project description:Sphingosine-1-phosphate (S1P) is an important bioactive lipid molecule in cell membrane metabolism and binds to G protein-coupled S1P receptors (S1PRs) to regulate embryonic development, physiological homeostasis, and pathogenic processes in various organs. S1PRs are lipid-sensing receptors and are therapeutic targets for drug development, including potential treatment of COVID-19. Herein, we present five cryo-electron microscopy structures of S1PRs bound to diverse drug agonists and the heterotrimeric Gi protein. Our structural and functional assays demonstrate the different binding modes of chemically distinct agonists of S1PRs, reveal the mechanical switch that activates these receptors, and provide a framework for understanding ligand selectivity and G protein coupling.

| S-EPMC8441948 | biostudies-literature

Activation and closed-state inactivation mechanisms of the human voltage-gated K<sub>V</sub>4 channel complexes.

Project description:The voltage-gated ion channel activity depends on both activation (transition from the resting state to the open state) and inactivation. Inactivation is a self-restraint mechanism to limit ion conduction and is as crucial to membrane excitability as activation. Inactivation can occur when the channel is open or closed. Although open-state inactivation is well understood, the molecular basis of closed-state inactivation has remained elusive. We report cryo-EM structures of human KV4.2 channel complexes in inactivated, open, and closed states. Closed-state inactivation of KV4 involves an unprecedented symmetry breakdown for pore closure by only two of the four S4-S5 linkers, distinct from known mechanisms of open-state inactivation. We further capture KV4 in a putative resting state, revealing how voltage sensor movements control the pore. Moreover, our structures provide insights regarding channel modulation by KChIP2 and DPP6 auxiliary subunits. Our findings elucidate mechanisms of closed-state inactivation and voltage-dependent activation of the KV4 channel.

| S-EPMC9271590 | biostudies-literature

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data