PspA adopts an ESCRT-III-like fold and remodels bacterial membranes

Summary PspA is the main effector of the phage shock protein (Psp) system and preserves the bacterial inner membrane integrity and function. Here, we present the 3.6 A resolution cryoelectron microscopy (cryo-EM) structure of PspA assembled in helical rods. PspA monomers adopt a canonical ESCRT-III fold in an extended open conformation. PspA rods are capable of enclosing lipids and generating positive membrane curvature. Using cryo-EM, we visualized how PspA remodels membrane vesicles into μm-sized structures and how it mediates the formation of internalized vesicular structures. Hotspots of these activities are zones derived from PspA assemblies, serving as lipid transfer platforms and lin…

PspA adopts an ESCRT-III-like fold and remodels bacterial membranes

SummaryPspA is the main effector of the phage shock protein (Psp) system and preserves the bacterial inner membrane integrity and function. Here, we present the 3.6 Å resolution cryo-EM structure of PspA assembled in helical rods. PspA monomers adopt a canonical ESCRT-III fold in an extended open conformation. PspA rods are capable of enclosing lipids and generate positive membrane curvature. Using cryo-EM we visualized how PspA remodels membrane vesicles into μm-sized structures and how it mediates the formation of internalized vesicular structures. Hot spots of these activities are zones derived from PspA assemblies, serving as lipid transfer platforms and linking previously separated lip…

Binding and/or hydrolysis of purine-based nucleotides is not required for IM30 ring formation

(19)F NMR screening of unrelated antimicrobial peptides shows that membrane interactions are largely governed by lipids.

AbstractMany amphiphilic antimicrobial peptides permeabilize bacterial membranes via successive steps of binding, re-alignment and/or oligomerization. Here, we have systematically compared the lipid interactions of two structurally unrelated peptides: the cyclic β-pleated gramicidin S (GS), and the α-helical PGLa. 19F NMR was used to screen their molecular alignment in various model membranes over a wide range of temperatures. Both peptides were found to respond to the phase state and composition of these different samples in a similar way. In phosphatidylcholines, both peptides first bind to the bilayer surface. Above a certain threshold concentration they can re-align and immerse more dee…

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…

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…

Binding and/or hydrolysis of purine‐based nucleotides is not required for IM30 ring formation

IM30, the inner membrane-associated protein of 30 kDa, is conserved in cyanobacteria and chloroplasts. Although its exact physiological function is still mysterious, IM30 is clearly essential for thylakoid membrane biogenesis and/or dynamics. Recently, a cryptic IM30 GTPase activity has been reported, albeit thus far no physiological function has been attributed to this. Yet, it is still possible that GTP binding/hydrolysis affects formation of the prototypical large homo-oligomeric IM30 ring and rod structures. Here, we show that the Synechocystis sp. PCC 6803 IM30 protein in fact is an NTPase that hydrolyzes GTP and ATP, but not CTP or UTP, with about identical rates. While IM30 forms lar…