Review, Reviews
Unveiling the molecular architecture of the mitochondrial respiratory chain of Acanthamoeba castellanii
Christian Q. Scheckhuber1, Sutherland K. Maciver2 and Alvaro de Obeso Fernandez del Valle1
This review provides a comprehensive overview of the mitochondrial res-piratory chain in A. castellanii, focusing on the key alternative components involved in oxidative phosphorylation and their roles in energy metabolism, stress response, and adaptation to various conditions.
Paving the way for new antimicrobial peptides through molecular de-extinction
Karen O. Osiro1, Abel Gil-Ley2, Fabiano C. Fernandes1,3, Kamila B. S. de Oliveira2, Cesar de la Fuente-Nunez4-7, Octavio L. Franco1,2
The advancement of artificial intelligence and molecular de-extinction offers a valuable opportunity not only to discover new antimicrobials but also to provide accurate in silico predictions, thereby shortening the path to addressing the global antibiotic resistance crisis.
Efflux pumps: gatekeepers of antibiotic resistance in Staphylococcus aureus biofilms
Shweta Sinha1, Shifu Aggarwal2,3 and Durg Vijai Singh1
This review aims to elucidate the complex relationship between efflux pumps, antibiotic resistance and biofilm formation in S. aureus with the aim to aid in the development of potential therapeutic targets for combating S. aureus infections, especially those associated with biofilms.
Understanding the molecular mechanisms of human diseases: the benefits of fission yeasts
Lajos Acs-Szabo, Laszlo-Attila Papp and Ida Miklos
Here we collect the latest laboratory protocols and bioinformatics tools for the fission yeasts to highlight the many possibilities available to the research community. In addition, we present several limiting factors that everyone should be aware of when working with yeast models.
Characterising glycosaminoglycans in human breastmilk and their potential role in infant health
Melissa Greenwood1,2, Patricia Murciano-Martínez3, Janet Berrington4, Sabine L Flitsch5, Sean Austin2 and Christopher Stewart1
Glycosaminoglycans are bioactive components present in breast milk and play a potential key role in determining infant health yet are overlooked by many contemporary studies. This review explores their relevance, use and characterisation techniques.
Neutralizing the threat: harnessing broadly neutralizing antibodies against HIV-1 for treatment and prevention
Juan C Becerra1, Lauren Hitchcock1, Khoa Vu1 and Johannes S Gach1
This review provides an overview of the advancements in HIV- 1-specific broadly neutralizing antibodies and discusses the insights gathered from recent clinical trials regarding their application in treating and preventing HIV-1 infection.
From microbes to medicine: harnessing the gut microbiota to combat prostate cancer
Anjali Yadav1, Meenakshi Kaushik1, Prabhakar Tiwari1 and Rima Dada1
The gut microbiome (GM) has been identified as a crucial factor in the development and progression of various diseases, including cancer. This review highlights the important role that the GM may play in the development and progression of prostate cancer, through its influence on chronic inflammation, immune modulation, and other pathogenic mechanisms.
The cAMP-PKA signalling crosstalks with CWI and HOG-MAPK pathways in yeast cell response to osmotic and thermal stress
Fiorella Galello1, Mariana Bermúdez-Moretti1, María Clara Ortolá Martínez1, Silvia Rossi1 and Paula Portela1
During industrial fermentation yeast strains are exposed to fluctuations in oxygen concentration, osmotic pressure, pH, ethanol concentration, nutrient availability and temperature. The scope of this review is to outline the advancement of knowledge about the cAMP-PKA signalling and the crosstalk of this pathway with the CWI and HOG-MAPK cascades in response to the environmental challenges heat and hyperosmotic stress.
Phospholipases A and Lysophospholipases in protozoan parasites
Perrine Hervé1, Sarah Monic1, Frédéric Bringaud1 and Loïc Rivière1
In this review, we summarize the literature on phospholipases and lysophospholipases in several protozoan parasites of medical relevance, and discuss the growing interest for them as potential drug and vaccine targets.
Effects of the intestinal microbiota on prostate cancer treatment by androgen deprivation therapy
November 15, 2022
Prostate cancer (PC) can be kept in check by androgen deprivation therapy (ADT, usually with the androgen synthesis inhibitor abiraterone acetate or the androgen receptor antagonist such as enzalutamide) until the tumor evolves to castration-resistant prostate cancer (CRPC). The transition of hormone-sensitive PC (HSPC) to CPRC has been explained by cancer cell-intrinsic resistance mechanisms. Recent data indicate that this transition is also marked by cancer cell-extrinsic mechanisms such as the failure of ADT-induced PC immunosurveillance, which depends on the presence of immunostimulatory bacteria in the gut. Moreover, intestinal bacteria that degrade drugs used for ADT, as well as bacteria that produce androgens, can interfere with the efficacy of ADT. Thus, specific bacteria in the gut serve as a source of testosterone, which accelerates prostate cancer progression, and men with CRPC exhibit an increased abundance of such bacteria with androgenic functions. In conclusion, the response of PC to ADT is profoundly influenced by the composition of the microbiota with its immunostimulatory, immunosuppressive and directly ADT-subversive elements.
Occurrence and potential mechanism of holin-mediated non-lytic protein translocation in bacteria
September 23, 2022
Holins are generally believed to generate large membrane lesions that permit the passage of endolysins across the cytoplasmic membrane of prokaryotes, ultimately resulting in cell wall degradation and cell lysis. However, there are more and more examples known for non-lytic holin-dependent secretion of proteins by bacteria, indicating that holins somehow can transport proteins without causing large membrane lesions. Phage-derived holins can be used for a non-lytic endolysin translocation to permeabilize the cell wall for the passage of secreted proteins. In addition, clostridia, which do not possess the Tat pathway for transport of folded proteins, most likely employ non-lytic holin-mediated transport also for secretion of toxins and bacteriocins that are incompatible with the general Sec pathway. The mechanism for non-lytic holin-mediated transport is (...)
Swimming faster despite obstacles: a universal mechanism behind bacterial speed enhancement in complex fluids
June 27, 2022
Bacteria constitute about 15% of global biomass and their natural environments often contain polymers and colloids, which show complex flow properties. It is crucial to study their motion in such environments to understand their growth and spreading as well as to design synthetic microswimmers for biomedical applications. Bacterial motion in complex viscous environments, although extensively studied over the past six decades, still remains poorly understood. In our recent study combining experimental data and theoretical analysis, we found a surprising similarity between bacterial motion in dilute colloidal suspensions and polymer solutions, which challenged the established view on the role of polymer dynamics on bacterial speed enhancement. We subsequently developed a physical model that provides a universal mechanism explaining bacterial speed enhancement (...)
A roadmap for designing narrow-spectrum antibiotics targeting bacterial pathogens
June 22, 2022
This comment discusses the article "Basis of narrow-spectrum activity of fidaxomicin on Clostridioides difficile" by Cao et al. (2022, Nature).
Breaking the clip for cargo unloading from motor proteins: mechanism and significance
May 19, 2022
The mitochondrion is an essential organelle involved in ATP generation, lipid metabolism, regulation of calcium ions, etc. Therefore, it should be inherited properly by newly generated cells. In the budding yeast Saccharomyces cerevisiae, mitochondria are passed on to daughter cells by the motor protein, Myo2, on the actin cable. The mitochondria and Myo2 are connected via the adaptor protein Mmr1. After reaching daughter cells, mitochondria are released from the actin-myosin machinery and move dynamically. In our recent paper (Obara K et al. (2022), Nat Commun, doi:10.1038/s41467-022-29704-8), we demonstrated that the regulated proteolysis of Mmr1 is required for the unloading of mitochondria from Myo2 in daughter cells. Sequential post-translational modifications of Mmr1, i.e., phosphorylation followed by ubiquitination, are essential for Mmr1 degradation and mitochondrial release from Myo2. Defects in Mmr1 degradation cause stacking and deformation of mitochondria at the bud-tip and bud-neck, where Myo2 accumulates. Compared to wild-type cells, mutant cells with defects in Mmr1 degradation possess an elevated mitochondrial membrane potential and produce higher levels of reactive oxygen species (ROS), along with hypersensitivity to oxidative stress.
Pirates of the haemoglobin
February 18, 2022
Not all treasure is silver and gold; for pathogenic bacteria, iron is the most precious and the most pillaged of metallic elements. Iron is essential for the survival and growth of all life; however free iron is scarce for bacteria inside human hosts. As a mechanism of defence, humans have evolved ways to store iron so as to render it inaccessible for invading pathogens, such as keeping the metal bound to iron-carrying proteins. For bacteria to survive within humans, they must therefore evolve counters to this defence to compete with these proteins for iron binding, or directly steal iron from them. (...)
An ionophore breaks the multi-drug-resistance of Acinetobacter baumannii
February 15, 2022
Within intensive care units, multi-drug resistant Acinetobacter baumannii outbreaks are a frequent cause of ventilator-associated pneumonia. During the on-going COVID-19 pandemic, patients who receive ventilator support experience a 2-fold increased risk of mortality when they contract a secondary A. baumannii pulmonary infection. In our recent paper (De Oliveira et al. (2022), Mbio, doi: 10.1128/mbio.03517-21), we demonstrate that the 8-hydroxquinoline ionophore, PBT2 breaks the resistance of A. baumannii to tetracycline class antibiotics. In vitro, the combination of PBT2 and zinc with either tetracycline, doxycycline, or tigecycline was shown to be bactericidal against multi-drug-resistant A. baumannii, (...)
Endomembrane remodeling and dynamics in Salmonella infection
December 27, 2021
Salmonellae are bacteria that cause moderate to severe infections in humans, depending on the strain and the immune status of the infected host. These pathogens have the particularity of residing in the cells of the infected host. They are usually found in a vacuolar compartment that the bacteria shape with the help of effector proteins. Following invasion of a eukaryotic cell, the bacterial vacuole undergoes maturation characterized by changes in localization, composition and morphology. In particular, membrane tubules stretching over the microtubule cytoskeleton are formed from the bacterial vacuole. Although these tubules do not occur in all infected cells, they are functionally important and promote intracellular replication. This review focuses on the role and significance of membrane compartment remodeling observed in infected cells and the bacterial and host cell pathways involved.