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Secretion systems are essential for bacteria to survive and manipulate their environment. The bacterial type VI secretion system (T6SS) generates the force needed for protein translocation by the contraction of a long polymer called sheath. The sheath is a six-start helical assembly of interconnected VipA/VipB subunits. The mechanism of T6SS sheath contraction is unknown. Here, we show that elongating the N-terminal VipA linker or eliminating charge of a specific VipB residue abolishes sheath contraction and delivery of effectors into target cells. Mass spectrometry analysis identified the inner tube protein Hcp, spike protein VgrG, and other components of the T6SS baseplate significantly enriched in samples of the stable non-contractile sheaths. The ability to lock the T6SS in the pre-firing state opens new possibilities for understanding its mode of action.
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http://dx.doi.org/10.15252/embr.201744416 | DOI Listing |
Cephalalgia
September 2025
Department of Molecular Physiology and Biophysics, University of Iowa, Iowa City, IA, USA.
Migraine is a complex neurological disorder involving multiple neuropeptides that modulate nociceptive and sensory pathways. The most studied peptide is calcitonin gene-related peptide (CGRP), which is a well-established migraine trigger and therapeutic target. Recently, another peptide, pituitary adenylate cyclase-activating polypeptide (PACAP), has emerged as an alternative target for migraine therapeutics.
View Article and Find Full Text PDFGenes Brain Behav
October 2025
Department of Pharmaceutical Sciences, College of Pharmacy, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA.
Major depressive disorder is a prevalent and debilitating psychiatric illness that produces significant disability. Clinical data suggest that the pathophysiology of depression is due, in part, to a dysregulation of inflammation and glutamate levels in the brain. The systemic administration of lipopolysaccharide (LPS) has been shown to induce depressive-like behaviors in mice.
View Article and Find Full Text PDFRev Med Liege
September 2025
Service de Chimie clinique, CHU Liège, Belgique.
Chronic kidney disease (CKD), heart failure (HF) and atherosclerotic cardiovascular disease (ASCVD) are pathologies that may remain silent for a long time and thus are largely underdiagnosed in clinical practice. The use of biomarkers may help detect people already suffering from these diseases at an early stage or at increased risk to develop them in a near future. The aim of this article is to discuss the place of the assays of albuminuria, natriuretic peptide (BNP/proBNP) and high-sensitivity troponin as well as lipoprotein(a) to help in the diagnosis and prognosis assessment of individuals at risk of presenting or developing a CKD, HF or ASCVD.
View Article and Find Full Text PDFRev Med Liege
September 2025
Service de Diabétologie, Nutrition et Maladies métaboliques, CHU Liège, Belgique.
Type 1 diabetes (T1D) is an autoimmune chronic disease that leads to the destruction of pancreatic beta cells and thus requires lifelong insulin therapy. Constraints and adverse events associated to insulin therapy are well known as well as the risk of long-term complications linked to chronic hyperglycaemia. Symptomatic T1D is preceded by a preclinical asymptomatic period, which is characterized by the presence of at least two auto-antibodies against beta cell without disturbances of blood glucose control (stage 1) or, in addition to immunological biomarkers, by the presence of mild dysglycaemia reflecting a defect of early insulin secretion (stage 2).
View Article and Find Full Text PDFVasc Specialist Int
September 2025
Department of Vascular Surgery, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
An abdominal aortic aneurysm (AAA) is defined as a localized dilation of the abdominal aorta measuring at least 1.5 times its normal diameter. If left untreated, AAA can progress to a life-threatening condition.
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