Neutrophils respond to invading bacteria by adopting a polarized morphology, migrating in the correct direction, and engulfing the bacteria. How neutrophils establish and precisely orient this polarity toward pathogens remains unclear. Here we report that in resting neutrophils, the ERM (ezrin, radixin, and moesin) protein moesin in its active form (phosphorylated and membrane bound) prevented cell polarization by inhibiting the small GTPases Rac, Rho, and Cdc42. Attractant-induced activation of myosin phosphatase deactivated moesin at the prospective leading edge to break symmetry and establish polarity. Subsequent translocation of moesin to the trailing edge confined the formation of a prominent pseudopod directed toward pathogens and prevented secondary pseudopod formation in other directions. Therefore, both moesin-mediated inhibition and its localized deactivation by myosin phosphatase are essential for neutrophil polarization and effective neutrophil tracking of pathogens.
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http://dx.doi.org/10.1084/jem.20140508 | DOI Listing |
Gastroenterology
December 2024
Department of Medicine, Center for Esophageal Diseases, Baylor University Medical Center and Center for Esophageal Research, Baylor Scott & White Research Institute, Dallas, TX. Electronic address:
Background & Aims: Dilated intercellular space (DIS) in esophageal epithelium, a sign of impaired barrier function, is a characteristic finding of GERD that also is found in obese patients without GERD. We have explored molecular mechanisms whereby adipose tissue products might impair esophageal barrier integrity.
Methods: We established cultures of visceral fat obtained during foregut surgery from obese and non-obese patients.
J Biol Chem
December 2024
Department of Medical Chemistry, Faculty of Medicine, University of Debrecen, Hungary. Electronic address:
Dysregulation of the expression levels and the activity of kinases/phosphatases is an intrinsic hallmark of tumor transformation and progression, as either as a primary cause or consequence. The myosin phosphatase (MP)/protein arginine methyltransferase 5 (PRMT5)/histone (H4) pathway is an oncogenic signaling pathway downregulating the gene expression of tumor suppressors. However, the upstream regulators of the pathway are unknown.
View Article and Find Full Text PDFZhongguo Zhong Yao Za Zhi
September 2024
Key Laboratory of Traditional Chinese Medicine for Prevention and Control of Regional High Incidence Diseases in Ningxia,Ministry of Education, Ningxia Medical University Yinchuan 750004, China.
Based on transcriptomics technology, this study investigated the molecular mechanisms of Xiangsha Liujunzi Decoction in treating chronic atrophic gastritis(CAG), which were confirmed through experimental validation. The CAG rat model was built by the MNNG composite multi-factor method, followed by a 90-day administration of Xiangsha Liujunzi Decoction. The study measured the rat body mass and 3-hour food intake in each group and observed the pathological changes in gastric tissue using HE staining.
View Article and Find Full Text PDFEur J Pharmacol
January 2025
Institute of Physiology, Brandenburg Medical School Theodor Fontane, Germany; Research Cluster, Molecular Mechanisms of Cardiovascular Diseases, Brandenburg Medical School Theodor Fontane, Neuruppin, Germany.
The femoral artery (FA) is the largest vessel in the hindlimb circulation and its proper tone regulation ensures adequate blood supply to muscle tissue. We investigated whether an alanine mutation of the targeting subunit of myosin-light-chain-phosphatase (MLCP), MYPT1, at threonine 696 (MYPT1-T696A/+), decisive for enzyme acivity, affects the responsiveness of young and old FAs (y-FAs and o-FAs) to activation of nitric-oxide/soluble-guanylate-cyclase/protein-kinase-G cascade (NO/sGC/PKG). Contractile responses of the vessels were measured by wire myography.
View Article and Find Full Text PDFJ Control Release
October 2023
Department of Life Sciences, Centre for Therapeutic Innovation, University of Bath, Bath BA2 7AY, UK. Electronic address:
The intestinal paracellular route of absorption is modulated via tight junction (TJ) structures located at the apical neck of polarized intestinal epithelial cells to restrict solute movement through the intercellular space between them. Tight junctions open or close in response to changes in the phosphorylation status of light chain (MLC) at position Ser-19. This phosphorylation event is primarily controlled by MLC kinase (MLCK) and MLC phosphatase (MLCP), the latter being a holoenzyme that involves interaction between protein phosphatase 1 (PP1) and myosin targeting protein 1 (MYPT1).
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