Microreviews – Page 8 – Microbial Cell

Microreviews, Review

Extracellular vesicles: An emerging platform in gram-positive bacteria

Swagata Bose^1,#, Shifu Aggarwal^1,#, Durg Vijai Singh^1,2 and Narottam Acharya¹

Extracellular vesicles (EVs) are secreted by both pathogenic and non-pathogenic bacteria to transfer biomolecules and facilitate intercellular communication. While EV secretion in gram-negative bacteria is well understood, less is known about gram-positive bacteria. This review explores the role of EVs involved in bacterial competition, survival, immune evasion, and infection of gram-positive bacteria and compares them to gram-negative counterparts.

Structural insights into the architecture and assembly of eukaryotic flagella

Narcis-Adrian Petriman¹ and Esben Lorentzen¹

Cilia and flagella are key structures in motility and signaling. This review highlights recent findings of cryo-EM studies that have mapped the structure of axonemal microtubules in Chlamydomonas reinhardtii, revealing over 30 associated proteins as well as recent researcht which focused on the trafficking complexes that transport components between the cell body and cilium.

Erythrocyte phospho-signalling is dynamically altered during infection with Plasmodium falciparum

Jack D. Adderley¹ and Christian Doerig¹

This article refers to the study "Analysis of erythrocyte signalling pathways during Plasmodium falciparum infection identifies targets for host-directed antimalarial intervention" by Adderley et al. (Nat Commun, 2020) that investigates how Plasmodium falciparum malaria parasites influence red blood cells. By tracking hanges in over 800 human proteins at different parasite stages they confirmed activation of the PAK-MEK pathway and discovered significant changes, particularly during the trophozoite stage. This suggests that kinases activated by the infection could be targeted for new antimalarial therapies.

Plant and fungal products that extend lifespan in Caenorhabditis elegans

Jan Martel^1,2, Cheng-Yeu Wu^1-3, Hsin-Hsin Peng^1,2,4, Yun-Fei Ko^2,5,6, Hung-Chi Yang⁷, John D. Young⁵ and David M. Ojcius^1,2,8

Caenorhabditis elegans' lifespan is extended by plant and fungal extracts activating pathways like autophagy and mitochondrial biogenesis. Low to moderate concentrations promote longevity, while high doses are harmful. This review explores the health benefits of these substances in humans.

A new role for proteins subunits of RNase P: stabilization of the telomerase holoenzyme

P. Daniela Garcia¹ and Virginia A. Zakian²

This article refers to the study "Stability and Nuclear Localization of Yeast Telomerase Depend on Protein Components of RNase P/MRP", by Garcia et al. (Nat Commun, 2020), showing that 3 essential proteins in Saccharomyces cerevisiae are vital for telomerase assembly and nuclear localization. In their mutants, telomerase is less mature, and telomeres are shorter. TLC1 is properly folded but remains in the cytoplasm, rather than moving to the nucleus, where it maintains telomeres.

Lipid droplet biogenesis from specialized ER subdomains

Vineet Choudhary¹ and Roger Schneiter²

This article refers to the paper "Seipin and Nem1 establish discrete ER subdomains to initiate yeast lipid droplet biogenesis" by Choudhary et al. (J Cell Biol, 2020), which deals with the formation of lipid droplets (LDs) at specific ER sites marked by the proteins Fld1 and Nem1. These proteins recruit enzymes such as Lro1 and Dga1 to initiate fat storage. Together, Fld1 and Nem1 define where LDs form by organising key proteins and lipids needed for their biogenesis.

From the Uncharacterized Protein Family 0016 to the GDT1 family: Molecular insights into a newly-characterized family of cation secondary transporters

Louise Thines¹, Jiri Stribny¹ and Pierre Morsomme¹

This review outlines how the formerly uncharacterized UPF0016 family, now known as the Gdt1 family, plays key roles in cation transport - especially Mn²⁺ - across species from bacteria to humans. These proteins are crucial for processes like glycosylation, photosynthesis, and calcium signaling, with functions linked to their localization in membranes such as the Golgi, chloroplast, and plasma membrane and by that highlighting their evolutionary conservation and physiological relevance, offering insights into their shared and distinct features across organisms.

A broad-spectrum antibiotic adjuvant SLAP-S25: one stone many birds

Meirong Song¹ and Kui Zhu¹

This article refers to the study "A broad-spectrum antibiotic adjuvant reverses multidrug-resistant Gram-negative pathogens" by Song et al. (Nat Microbiol, 2020), which deals with the growing threat of antibiotic resistance, with few new drugs being developed for decades. The study found that the peptide SLAP-S25 enhances the efficacy of several antibiotics against resistant Gram-negative bacteria by disrupting their membranes, thereby increasing drug uptake. This suggests that bacterial membranes are promising targets for new antibiotic adjuvants.

Hiding in plain sight: vesicle-mediated export and transmission of prion-like proteins

Mehdi Kabani¹

This article relates to the study "Glucose availability dictates the export of the soluble and prion forms of Sup35p via periplasmic or extracellular vesicles" by Kabani et al. (Mol Microbiol, 2020) that provides compelling evidence that yeast prions, such as Sup35p in its infectious [PSI⁺] state, can be exported via both extracellular vesicles (EVs) and periplasmic vesicles (PVs), with this export being modulated by environmental glucose levels. The discovery that prion particles are released in high amounts through PVs during glucose starvation adds a new dimension to our understanding of prion transmission and opens up fascinating possibilities for exploring vesicle-mediated spread of protein aggregates in neurodegenerative diseases using yeast as a model system.

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Toxin-mediated gene regulatory mechanism in Staphylococcus aureus

December 29, 2016

This article comments on work published by Joo et al. (MBio, 2016), which describes the first molecular regulatory mechanism exerted by an S. aureus toxin, setting a paradigmatic example of how S. aureus toxins may influence cell functions to adjust them to times of toxin production.

NprR, a moonlighting quorum sensor shifting from a phosphatase activity to a transcriptional activator

November 5, 2016

This article comments on work published by Perchat et al. (PLoS Pathog, 2016), which demonstrates that, in the absence of the signaling peptide NprX, the sensor NprR is a dimer, which negatively controls sporulation in Bacillus thuringiensis, independently of its transcription factor activity.

The interaction between herpes simplex virus 1 genome and promyelocytic leukemia nuclear bodies (PML-NBs) as a hallmark of the entry in latency

November 4, 2016

This article comments on work published by Maroul et al. (PLoS Pathog, 2016), which demonstrates that the interaction of the viral genomes with the nuclear architecture and specifically the promyelocytic leukemia nuclear bodies is a major determinant for the entry of HSV-1 into latency.

Francisella IglG protein and the DUF4280 proteins: PAAR-like proteins in non-canonical Type VI secretion systems?

October 30, 2016

This article comments on work published by Rigard et al. (PLoS Pathog, 2013), which identified the function of IgIG, a protein of unknown function, encoded within the Francisella Pathogenicity Island.

B cell-helping functions of gut microbial metabolites

September 23, 2016

This article comments on work published by Kim et al. (Cell Host & Microbe, 2016), which showed that the microbial metabolites short-chain fatty acids (SCFAs) regulate the metabolism and gene expression in B cells to promote antibody production.

Cryptococcus flips its lid – membrane phospholipid asymmetry modulates antifungal drug resistance and virulence

August 1, 2016

This article comments on work published by Huang et al. (MBio, 2016), which reported that in the pathogenic fungus Cryptococcus neoformans loss of lipid flippase activity sensitized cryptococcal cells to multiple classes of antifungal drugs and abolished fungal virulence in murine models.