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Remodeling of vacuolar membranes mediated by endosomal sorting complex required for transport (ESCRT) is critical for microautophagy induction in budding yeast. Nutrient depletion and inactivation of target of rapamycin complex 1 (TORC1) protein kinase elicit recruitment of the ESCRT-0 complex (Vps27–Hse1) onto vacuolar membranes and ESCRT-mediated microautophagy induction. Mitotic protein phosphatase Cdc14 antagonizes TORC1-mediated phosphorylation in macroautophagy induction after nutrient starvation and TORC1 inactivation. Here, we report that Cdc14 downregulates microautophagy induction after TORC1 inactivation. Cdc14 dysfunction stimulated the vacuolar membrane recruitment of Hse1, but not Vps27, after TORC1 inactivation, promoting ESCRT-0 complex formation. Conversely, overexpression of CDC14 compromises Hse1 recruitment on vacuolar membranes and microautophagy induction after TORC1 inactivation. Thus, Cdc14 phosphatase regulates the fluxes of two types of autophagy in the opposite directions, namely, it elicits macroautophagy and attenuates microautophagy. • Cdc14 dysfunction facilitates microautophagy induction after TORC1 inactivation. • Cdc14 dysfunction elicits the vacuolar membrane recruitment of Hse1, but not Vps27. • Overexpression of CDC14 compromises ESCRT-mediated microautophagy induction. • Cdc14 upregulates macroautophagy and downregulates microautophagy. [ABSTRACT FROM AUTHOR]

The degradation of nucleolar proteins – nucleophagy – is elicited by nutrient starvation or the inactivation of target of rapamycin complex 1 (TORC1) protein kinase in budding yeast. Prior to nucleophagy, nucleolar proteins migrate to the nucleus–vacuole junction (NVJ), where micronucleophagy occurs, whereas rDNA (rRNA gene) repeat regions are condensed and escape towards NVJ-distal sites. This suggests that the NVJ controls nucleolar dynamics from outside of the nucleus after TORC1 inactivation, but its molecular mechanism is unclear. Here, we show that sorting nexin (SNX) Mdm1, an inter-organelle tethering protein at the NVJ, mediates TORC1 inactivation-induced nucleolar dynamics. Furthermore, Mdm1 was required for proper nucleophagic degradation of nucleolar proteins after TORC1 inactivation, where it was dispensable for the induction of nucleophagic flux itself. This indicated that nucleophagy and nucleolar dynamics are independently regulated by TORC1 inactivation. Finally, Mdm1 was critical for survival during nutrient starvation conditions. Mutations of SNX14, a human Mdm1 homolog, cause neurodevelopmental disorders. This study provides a novel insight into relationship between sorting nexin-mediated microautophagy and neurodevelopmental disorders. • The NVJ protein Mdm1 mediates TORC1 inactivation-induced nucleolar dynamics. • Mdm1 is required for proper nucleophagic degradation of nucleolar proteins. • Mdm1 is dispensable for the induction of nucleophagic flux itself. • Mdm1 is critical for survival during nutrient starvation conditions. [ABSTRACT FROM AUTHOR]

Deformation of vacuolar membranes mediated by endosomal sorting complex required for transport (ESCRT) is necessary for microautophagy. Target of rapamycin complex 1 (TORC1) protein kinase negatively regulates ESCRT-0 (Vps27–Hse1) recruitment onto vacuolar membranes and microautophagy induction. However, whether and how protein phosphatase regulates these events is unknown. Here, we show that the TORC1-downstream protein phosphatase PP2A–Cdc55 is important for these events after TORC1 inactivation in budding yeast. Loss of PP2A–Cdc55 compromised vacuolar localization of Hse1, but not Vps27. This study revealed that the orchestrated action of PP2A induces microautophagy upon TORC1 inactivation. • PP2A–Cdc55 promotes microautophagy induction after TORC1 inactivation. • PP2A–Cdc55 promotes vacuolar localization of Hse1 after TORC1 inactivation. • PP2A–Cdc55 promotes ESCRT-0 complex formation on vacuolar membranes. [ABSTRACT FROM AUTHOR]

Microautophagy is promoted after nutrient starvation and inactivation of target of rapamycin complex 1 (TORC1) kinase. Invagination of vacuolar membranes by endosomal sorting complex required for transport (ESCRT) is required for microautophagy. Vps27, a subunit of ESCRT-0, is recruited onto vacuolar membranes via dephosphorylation after TORC1 inactivation. Here, we showed that Hse1, another ESCRT-0 subunit, is also recruited onto vacuolar membranes after TORC1 inactivation, promoting formation of ESCRT-0 complex on vacuolar membranes. Hse1 recruitment was dependent on Vps27, whereas Vps27 recruitment was independent of Hse1. Not only Vps27 but also Hse1 was required for ESCRT-III recruitment onto vacuolar membranes and microautophagy induction after TORC1 inactivation. This study revealed that ESCRT-0 (Vps27–Hse1) complex formation on vacuolar membranes is important for microautophagy inactivation after TORC1 inactivation. • TORC1 inactivation promotes ESCRT-0 complex formation on vacuolar membranes. • Hse1 recruitment onto vacuolar membranes is dependent on Vps27, but not vise versa. • Both Vps27 and Hse1 are required for TORC1 inactivation-induced microautophagy. [ABSTRACT FROM AUTHOR]

A total of five compounds, namely lupeol (1), β-amyrin (2), stigmasterol (3), β-sitosterol (4) and 7,3'-dimethoxyluteolin (5) were isolated from a methanol extract of Albizia chinensis stem bark. The structures of the isolated compounds were established using nuclear magnetic resonance (NMR) spectroscopic studies, as well as using comparative thin layer chromatography (co-TLC) with standards. The methanol extract of the A. chinensis stem bark and its n-hexane-, carbon tetrachloride-, chloroform- and aqueous-soluble partitionates were evaluated for antioxidant activity with 1,1-diphenyl- 2-picrylhydrazyl (DPPH), Folin-Ciocalteu reagent and phosphomolybdenum total antioxidant assays, where butylated hydroxytoluene (BHT) and ascorbic acid were used as standards. The carbon tetrachloride-soluble fraction contained a moderate amount of phenolic compounds (60.76 ± 0.45 mg of GAE/g of extract) and it exhibited significant free radical-scavenging activity (IC50 10.21 ± 0.84 μg ml-1). A positive correlation was observed between the total phenolic content and the total antioxidant capacity of A. chinensis. The general toxicity was determined using a brine shrimp lethality bioassay, where the carbon tetrachloride (LC50 0.608 ± 0.19 μg ml-1) and hexane (LC50 0.785 ± 0.26 μg ml-1) soluble partitionates had considerable bioactive properties. The crude extract and its chloroform- and aqueous-soluble fractions displayed significant antimicrobial activity against eighteen microorganisms with inhibition zones ranging from 7.0 mm to 26.0 mm. [ABSTRACT FROM AUTHOR]

Chromosomes have their own territories and dynamically translocate in response to internal and external cues. However, whether and how territories and the relocation of chromosomes are controlled by other intracellular organelles remains unknown. Upon nutrient starvation and target of rapamycin complex 1 (TORC1) inactivation, micronucleophagy, which preferentially degrades nucleolar proteins, occurs at the nucleus–vacuole junction (NVJ) in budding yeast. Ribosomal DNA (rDNA) is condensed and relocated against the NVJ, whereas nucleolar proteins move towards the NVJ for micronucleophagic degradation, causing dissociation of nucleolar proteins from rDNA. These findings imply that the NVJ is the critical platform in the directional movements of rDNA and nucleolar proteins. Here, we show that cells lacking the NVJ (NVJΔ cells) largely lost rDNA condensation and rDNA–nucleolar protein separation after TORC1 inactivation. The macronucleophagy receptor Atg39, an outer nuclear membrane protein, accumulated at the NVJ and was degraded by micronucleophagy. These suggested that macronucleophagy is also dependent on the presence of the NVJ. However, micronucleophagy, but not macronucleophagy, was abolished in NVJΔ cells. This study clearly demonstrated that vacuoles controls intranuclear events, nucleolar dynamics, from outside of the nucleus via the NVJ under the control of TORC1. • Cells lacking the NVJ largely lose rDNA condensation after TORC1 inactivation. • NVJΔ cells abrogate rDNA–nucleolar protein separation after TORC1 inactivation. • Thus, vacuoles control intranuclear events from outside of the nucleus via the NVJ. [ABSTRACT FROM AUTHOR]

The pharmacological actions of benzylisoquinoline alkaloids are quite substantial, and have recently attracted much attention. One of the principle benzylisoquinoline alkaloids has been found in the unripe seed capsules of Papaver somniferum L. Although it lacks analgesic effects and is unrelated to the compounds in the morphine class, it is a peripheral vasodilator and has a direct effect on vessels. It is reported to inhibit the cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP) phosphodiesterase in smooth muscles, and it has been observed to increase intracellular levels of cAMP and cGMP. It induces coronary, cerebral, and pulmonary artery dilatation and helps to lower cerebral vascular resistance and enhance cerebral blood flow. Current pharmacological research has revealed that papaverine demonstrates a variety of biological activities, including activity against erectile dysfunction, postoperative vasospasms, and pulmonary vasoconstriction, as well as antiviral, cardioprotective, anti-inflammatory, anticancer, neuroprotective, and gestational actions. It was recently demonstrated that papaverine has the potential to control SARS-CoV-2 by preventing its cytopathic effect. These experiments were carried out both in vitro and in vivo and require an extensive understanding of the mechanisms of action. With its multiple mechanisms, papaverine can be considered as a natural compound that is used to develop therapeutic drugs. To validate its applications, additional research is required into its precise therapeutic mechanisms as well as its acute and chronic toxicities. Therefore, the goal of this review is to discuss the major studies and reported clinical studies looking into the pharmacological effects of papaverine and the mechanisms of action underneath these effects. Additionally, it is recommended to conduct further research via significant pharmacodynamic and pharmacokinetic studies. [ABSTRACT FROM AUTHOR]

[Display omitted] • Vps27 recruitment onto vacuolar membranes after TORC1 inactivation requires PI3KCII. • PI3KCII is required for microautophagy induction after TORC1 inactivation. • A critical role of PI3P on microautophagy induction is Vps27 recruitment. • Vps27 function on vacuolar membranes is critical for survival in starved cells. Phosphatidylinositol 3-phosphate (PI3P), a scaffold of membrane-associated proteins required for diverse cellular events, is produced by Vps34-containing phosphatidylinositol 3-kinase (PI3K). PI3K complex I (PI3KCI)-generated PI3P is required for macroautophagy, whereas PI3K complex II (PI3KCII)-generated PI3P is required for endosomal sorting complex required for transport (ESCRT)-mediated multi-vesicular body (MVB) formation in late endosomes. ESCRT also promotes vacuolar membrane remodeling in microautophagy after nutrient starvation and inactivation of target of rapamycin complex 1 (TORC1) protein kinase in budding yeast. Whereas PI3KCI and macroautophagy are critical for the nutrient starvation response, the physiological roles of PI3KCII and microautophagy during starvation are largely unknown. Here, we showed that PI3KCII-produced PI3P on vacuolar membranes is required for microautophagy induction and survival in nutrient-stressed conditions. PI3KCII is required for Vps27 (an ESCRT-0 component) recruitment and ESCRT-0 complex formation on vacuolar surfaces after TORC1 inactivation. Forced recruitment of Vps27 onto vacuolar membranes rescued the defect in microautophagy induction in PI3KCII-deficient cells, indicating that a critical role of PI3P on microautophagy induction is Vps27 recruitment onto vacuolar surfaces. Finally, vacuolar membrane-associated Vps27 was able to recover survival during nutrient starvation in cells lacking PI3KCII or Vps27. This study revealed that the PI3KCII–PI3P–Vps27 axis on vacuolar membranes is critical for ESCRT-mediated microautophagy induction and nutrient stress adaptation. [ABSTRACT FROM AUTHOR]