Ubiquitin-Dependent And Independent Signals In Selective Autophagy.
Selective autophagy regulates the abundance of specific cellular components via a specialized arsenal of factors, termed autophagy receptors, that target protein complexes, aggregates, and whole organelles into lysosomes. Autophagy receptors bind to LC3/GABARAP proteins on phagophore and autophagosome membranes, and recognize signals on cargoes to deliver them to autophagy. Ubiquitin (Ub), a well-known signal for the degradation of polypeptides in the proteasome, also plays an important role in the recognition of cargoes destined for selective autophagy. In addition, a variety of cargoes are committed to selective autophagy pathways by Ub-independent mechanisms employing protein-protein int…
Famotidine inhibits toll-like receptor 3-mediated inflammatory signaling in SARS-CoV-2 infection
Apart from prevention using vaccinations, the management options for COVID-19 remain limited. In retrospective cohort studies, use of famotidine, a specific oral H2 receptor antagonist (antihistamine), has been associated with reduced risk of intubation and death in patients hospitalized with COVID-19. In a case series, nonhospitalized patients with COVID-19 experienced rapid symptom resolution after taking famotidine, but the molecular basis of these observations remains elusive. Here we show using biochemical, cellular, and functional assays that famotidine has no effect on viral replication or viral protease activity. However, famotidine can affect histamine-induced signaling processes i…
The integration of autophagy and cellular trafficking pathways via RAB GAPs.
Macroautophagy is a conserved degradative pathway in which a double-membrane compartment sequesters cytoplasmic cargo and delivers the contents to lysosomes for degradation. Efficient formation and maturation of autophagic vesicles, so-called phagophores that are precursors to autophagosomes, and their subsequent trafficking to lysosomes relies on the activity of small RAB GTPases, which are essential factors of cellular vesicle transport systems. The activity of RAB GTPases is coordinated by upstream factors, which include guanine nucleotide exchange factors (RAB GEFs) and RAB GTPase activating proteins (RAB GAPs). A role in macroautophagy regulation for different TRE2-BUB2-CDC16 (TBC) dom…
SIK2 orchestrates actin-dependent host response upon Salmonella infection
Significance Through conducting quantitative proteomics upon Salmonella infection, we identified a SIK2 signaling network, implementing the kinase into a so far concealed biological function. Our data exposed SIK2 as a central orchestrator of an actin regulatory network, coordinating the stability of Salmonella-containing vacuole (SCV) and cellular actin assembly, in order to limit the acute phase of the infection. Most strikingly, SIK2 is not exclusively acting locally on actin assembly associated with the SCV but impacts the actin cytoskeleton architecture in its entirety upon Salmonella infection. Our work provides a mechanistic framework for how the actin cytoskeleton is regulated and h…
Autophagy
Klionsky, Daniel J. et al.
PLEKHM1 Regulates Salmonella-Containing Vacuole Biogenesis and Infection
Abstract: The host endolysosomal compartment is often manipulated by intracellular bacterial pathogens. Salmonella (Salmonella enterica serovar Typhimurium) secrete numerous effector proteins, including SifA, through a specialized type III secretion system to hijack the host endosomal system and generate the Salmonella-containing vacuole (SCV). To form this replicative niche, Salmonella targets the Rab7 GTPase to recruit host membranes through largely unknown mechanisms. We show that Pleckstrin homology domain-containing protein family member 1 (PLEKHM1), a lysosomal adaptor, is targeted by Salmonella through direct interaction with SifA. By binding the PLEKHM1 PH2 domain, Salmonella utiliz…
Guidelines for the use and interpretation of assays for monitoring autophagy (3rd edition)
Seuls les 100 premiers auteurs dont les auteurs INRA ont été entrés dans la notice. La liste complète des auteurs et de leurs affiliations est accessible sur la publication.; International audience; In 2008 we published the first set of guidelines for standardizing research in autophagy. Since then, research on this topic has continued to accelerate, and many new scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Accordingly, it is important to update these guidelines for monitoring autophagy in different organisms. Various reviews have described the range of assays that have been used for this purpose. Nevertheless, there continues…
RAB3GAP1 and RAB3GAP2 modulate basal and rapamycin-induced autophagy
Macroautophagy is a degradative pathway that sequesters and transports cytosolic cargo in autophagosomes to lysosomes, and its deterioration affects intracellular proteostasis. Membrane dynamics accompanying autophagy are mostly elusive and depend on trafficking processes. RAB GTPase activating proteins (RABGAPs) are important factors for the coordination of cellular vesicle transport systems, and several TBC (TRE2-BUB2-CDC16) domain-containing RABGAPs are associated with autophagy. Employing C. elegans and human primary fibroblasts, we show that RAB3GAP1 and RAB3GAP2, which are components of the TBC domain-free RAB3GAP complex, influence protein aggregation and affect autophagy at basal an…
Ubiquitin-independent function of optineurin in autophagic clearance of protein aggregates.
Summary Aggregation of misfolded proteins and the associated loss of neurons are considered a hallmark of numerous neurodegenerative diseases. Optineurin is present in protein inclusions observed in various neurodegenerative diseases including amyotrophic lateral sclerosis (ALS), Huntington's disease, Alzheimer's disease, Parkinson's disease, Creutzfeld-Jacob disease and Pick's disease. Optineurin deletion mutations have also been described in ALS patients. However, the role of optineurin in mechanisms of protein aggregation remains unclear. In this report, we demonstrate that optineurin recognizes various protein aggregates via its C-terminal coiled-coil domain in a ubiquitin-independent m…
Activation of mitogen-activated protein kinase by the bradykinin B2receptor is independent of receptor phosphorylation and phosphorylation-triggered internalization
Recent evidence suggests that serine/threonine phosphorylation and internalization of beta2-adrenergic receptors play critical roles in signalling to the mitogen-activated protein kinase cascade. To investigate whether this represents a general mechanism employed by G protein-coupled receptors, we studied the requirement of these processes in the activation of mitogen-activated protein kinase by G alpha(q)-coupled bradykinin B2 receptors. Mutant B2 receptors impaired in receptor phosphorylation and internalization are fully capable to activate mitogen-activated protein kinase. Bradykinin-induced long-term effects on mitogenic signalling monitored by measuring the transcriptional activity of…
Guidelines for the use and interpretation of assays for monitoring autophagy (4th edition) 1
Contains fulltext : 232759.pdf (Publisher’s version ) (Closed access) In 2008, we published the first set of guidelines for standardizing research in autophagy. Since then, this topic has received increasing attention, and many scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Thus, it is important to formulate on a regular basis updated guidelines for monitoring autophagy in different organisms. Despite numerous reviews, there continues to be confusion regarding acceptable methods to evaluate autophagy, especially in multicellular eukaryotes. Here, we present a set of guidelines for investigators to select and interpret methods to…
Autophagy
In 2008, we published the first set of guidelines for standardizing research in autophagy. Since then, this topic has received increasing attention, and many scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Thus, it is important to formulate on a regular basis updated guidelines for monitoring autophagy in different organisms. Despite numerous reviews, there continues to be confusion regarding acceptable methods to evaluate autophagy, especially in multicellular eukaryotes. Here, we present a set of guidelines for investigators to select and interpret methods to examine autophagy and related processes, and for reviewers to provide…
Erratum
Author(s): Klionsky, DJ; Abdelmohsen, K; Abe, A; Abedin, MJ; Abeliovich, H; Arozena, AA; Adachi, H; Adams, CM; Adams, PD; Adeli, K; Adhihetty, PJ; Adler, SG; Agam, G; Agarwal, R; Aghi, MK; Agnello, M; Agostinis, P; Aguilar, PV; Aguirre-Ghiso, J; Airoldi, EM; Ait-Si-Ali, S; Akematsu, T; Akporiaye, ET; Al-Rubeai, M; Albaiceta, GM; Albanese, C; Albani, D; Albert, ML; Aldudo, J; Algul, H; Alirezaei, M; Alloza, I; Almasan, A; Almonte-Beceril, M; Alnemri, ES; Alonso, C; Altan-Bonnet, N; Altieri, DC; Alvarez, S; Alvarez-Erviti, L; Alves, S; Amadoro, G; Amano, A; Amantini, C; Ambrosio, S; Amelio, I; Amer, AO; Amessou, M; Amon, A; An, Z; Anania, FA; Andersen, SU; Andley, UP; Andreadi, CK; Andrieu-Ab…
RAB3GAP1 and RAB3GAP2 modulate basal and rapamycin-induced autophagy
Macroautophagy is a degradative pathway that sequesters and transports cytosolic cargo in autophagosomes to lysosomes, and its deterioration affects intracellular proteostasis. Membrane dynamics accompanying autophagy are mostly elusive and depend on trafficking processes. RAB GTPase-activating proteins (RABGAPs) are important factors for the coordination of cellular vesicle transport systems, and several TBC (TRE2-BUB2-CDC16) domain-containing RABGAPs are associated with autophagy. Employing C. elegans and human primary fibroblasts, we show that RAB3GAP1 and RAB3GAP2, which are components of the TBC domain-free RAB3GAP complex, influence protein aggregation and affect autophagy at basal an…