Autophagy is an intracellular bulk degradation/recycling system that turns over cellular constituents and also functions to degrade intracellular foreign microbial invaders by a process termed xenophagy (antimicrobial autophagy). We previously showed that intracellular group A Streptococcus (GAS) organisms are captured by xenophagosomes, then degraded following fusion with lysosomes. Very recently, we analyzed the molecular mechanism underlying xenophagosome/lysosome fusion and found that endocytic soluble N-ethylmaleimide-sensitive factor attachment protein receptors (SNAREs) were involved. Knockdown of the combinational SNARE proteins Vti1b and VAMP8 with siRNAs disturbed autophagic fusion with lysosomes, and cellular bactericidal efficiency was significantly diminished. Furthermore, knockdown of those SNAREs inhibited the fusion of canonical autophagosomes with lysosomes. In addition, important findings showed that Vti1b is derived from autophagic compartments, whereas VAMP8 originates from lysosomes. Together, these results strongly suggest that SNARE proteins Vti1b and VAMP8 mediate the fusion of antimicrobial and canonical autophagosomes with lysosomes, an essential event for autophagic degradation.
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http://dx.doi.org/10.4161/cib.3.4.12030 | DOI Listing |
Cell Mol Biol Lett
January 2025
University Cote d'Azur, Inserm, C3M, Nice, France.
Vacuolization of hematopoietic precursors cells is a common future of several otherwise non-related clinical settings such as VEXAS, Chediak-Higashi syndrome and Danon disease. Although these disorders have a priori nothing to do with one other from a clinical point of view, all share abnormal vacuolization in different cell types including cells of the erythroid/myeloid lineage that is likely the consequence of moderate to drastic dysfunctions in the ubiquitin proteasome system and/or the endo-lysosomal pathway. Indeed, the genes affected in these three diseases UBA1, LYST or LAMP2 are known to be direct or indirect regulators of lysosome trafficking and function and/or of different modes of autophagy.
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January 2025
Department of Cardiology, Angiology and Pneumology, University Hospital Heidelberg, Heidelberg, Germany.
Pathological cardiac remodeling is a maladaptive response that leads to changes in the size, structure, and function of the heart. These changes occur due to an acute or chronic stress on the heart and involve a complex interplay of hemodynamic, neurohormonal and molecular factors. As a critical regulator of cell growth, protein synthesis and autophagy mechanistic target of rapamycin complex 1 (mTORC1) is an important mediator of pathological cardiac remodeling.
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January 2025
The Department of Orthopedics, The First Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, Guangdong, China.
The death of osteoblasts induced by glucocorticoid (GC)-mediated oxidative stress plays a crucial role in the development of steroid-induced osteonecrosis of the femoral head (SIONFH). Improving bone formation driven by osteoblasts has shown promising outcomes in the prognosis of SIONFH. Isovitexin has demonstrated antioxidant properties, but its therapeutic effects on GC-induced oxidative stress and SIONFH remain unexplored.
View Article and Find Full Text PDFInt J Biol Macromol
January 2025
National Animal Protozoa Laboratory and School of Veterinary Medicine, China Agricultural University, Beijing 100193, China; Shenzhen Key Laboratory of Pathogenic Microbes and Biosafety, and Laboratory of Zoonotic Diseases, School of Public Health (Shenzhen), Sun Yat-Sen University, Shenzhen Campus, Shenzhen 518107, China. Electronic address:
Toxoplasma gondii is an intracellular and parasitic protozoon that harbors specialized cellular structures and molecular mechanisms, including the Plant-like Vacuolar Compartment (PLVAC). The PLVAC performs multifaceted roles in the parasite, contributing to ion homeostasis, proteolysis, pH regulation, and autophagy. Despite significant efforts over the past decade to characterize the PLVAC, the proteins localized to this organelle remain largely unidentified.
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January 2025
Department of Biochemistry and Molecular Biology, Graduate School of Medicine, The University of Tokyo, Tokyo 113-0033, Japan. Electronic address:
Autophagy is the cellular processes that transport cytoplasmic components to lysosomes for degradation. It plays essential physiological roles, including in adaptation to environmental changes such as starvation and maintaining intracellular quality control. Recently, its links to aging and disease have garnered substantial attention.
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