The lipid-rich cell wall of Mycobacterium tuberculosis, the agent of tuberculosis, serves as an effective barrier against many chemotherapeutic agents and toxic host cell effector molecules, and it may contribute to the mechanism of persistence. Mycobacterium tuberculosis strains mutated in a 13-gene operon called mce1, which encodes a putative ABC lipid transporter, induce aberrant granulomatous response in mouse lungs. Because of the postulated role of the mce1 operon in lipid importation, we compared the cell wall lipid composition of wild type and mce1 operon mutant M. tuberculosis H37Rv strains. High resolution mass spectrometric analyses of the mce1 mutant lipid extracts showed unbound mycolic acids to accumulate in the cell wall. Quantitative analysis revealed a 10.7 fold greater amount of free mycolates in the mutant compared to that of the wild type strain. The free mycolates were comprised of alpha, methoxy and keto mycolates in the ratio 1:0.9:0.6, respectively. Since the mce1 operon is regulated in vivo, the free mycolates that accumulate during infection may serve as a barrier for M. tuberculosis against toxic products and contribute to the pathogen's persistence.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1007/s12275-013-3092-y | DOI Listing |
J Exp Bot
January 2025
Ministry of Education Key Laboratory of Molecular and Cellular Biology; Hebei Research Center of the Basic Discipline of Cell Biology; Hebei Collaboration Innovation Center for Cell Signaling and Environmental Adaptation; Hebei Key Laboratory of Molecular and Cellular Biology; College of Life Sciences, Hebei Normal University, 050024 Shijiazhuang, China.
A well-constructed pollen wall is essential for pollen fertility, which relies on the contribution of tapetum. Our results demonstrate an essential role of the tapetum-expressed protein phosphatase 2A (PP2A) B'α and B'β in pollen wall formation. The b'aβ double mutant pollen grains harbored sticky remnants and tectum breakages, resulting in failed release.
View Article and Find Full Text PDFJ Agric Food Chem
January 2025
Faculty of Chemistry, Biotechnology, and Food Science, NMBU Norwegian University of Life Sciences, P.O. Box 5003, 1432 Aas, Norway.
Carrageenans are sulfated polysaccharides found in the cell wall of certain red seaweeds. They are widely used in the food industry for their gelling and stabilizing properties. In nature, carrageenans undergo enzymatic modification and degradation by marine organisms.
View Article and Find Full Text PDFJ Agric Food Chem
January 2025
Key Laboratory of Agricultural Biosafety and Green Production of Upper Yangtze River (Ministry of Education), College of Plant Protection, Southwest University, Chongqing 400715, China.
The mitochondrial voltage-dependent anion channel (VDAC) is the major channel in the mitochondrial outer membrane for metabolites and ions. VDACs also regulate a variety of biological processes, which vary in the number of VDAC isoforms across different eukaryotes. However, little is known about VDAC-mediated biocontrol traits in biocontrol fungi.
View Article and Find Full Text PDFInt J Mol Sci
December 2024
Division of Neonatology, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA.
Mammalian blood cells originate from specialized 'hemogenic' endothelial (HE) cells in major arteries. During the endothelial-to-hematopoietic transition (EHT), nascent hematopoietic stem cells (HSCs) bud from the arterial endothelial wall and enter circulation, destined to colonize the fetal liver before ultimately migrating to the bone marrow. Mechanisms and processes that facilitate EHT and the release of nascent HSCs are incompletely understood, but may involve signaling from neighboring vascular endothelial cells, stromal support cells, circulating pre-formed hematopoietic cells, and/or systemic factors secreted by distal organs.
View Article and Find Full Text PDFInt J Mol Sci
December 2024
Department of Animal Physiology, The Kielanowski Institute of Animal Physiology and Nutrition, Polish Academy of Sciences, Instytucka 3, 05-110 Jabłonna, Poland.
The aim of this study was to elucidate the impact of porcine pancreatic enzymes (Creon pancrelipase) in comparison to microbial-derived alpha amylase (MD amylase) on the small intestine wall structure, mucosal glycogen accumulation, and enterocyte turnover. The impact of enzyme supplementation on the small intestine was explored in 18 pigs with surgically induced exocrine pancreatic insufficiency (EPI). Four healthy pigs served as the control group.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!