Many neurotransmitters are organic ions that carry a net charge, and their release from secretory vesicles is therefore an electrodiffusion process. The selectivity of early exocytotic fusion pores is investigated by combining electrodiffusion theory, measurements of amperometric foot signals from chromaffin cells with anion substitution, and molecular dynamics simulation. The results reveal that very narrow fusion pores are cation selective, but more dilated fusion pores become anion permeable. The transition occurs around a fusion pore conductance of ∼300 pS. The cation selectivity of a narrow fusion pore accelerates the release of positively charged transmitters such as dopamine, noradrenaline, adrenaline, serotonin, and acetylcholine, while glutamate release may require a more dilated fusion pore.
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http://dx.doi.org/10.1016/j.celrep.2021.109580 | DOI Listing |
Materials (Basel)
January 2025
Mechanical and Aerospace Engineering Department, Utah State University, Logan, UT 84322-4130, USA.
Laser powder bed fusion (LPBF) is an additive manufacturing process that has gained interest for its material fabrication due to multiple advantages, such as the ability to print parts with small feature sizes, good mechanical properties, reduced material waste, etc. However, variations in the key process parameters in LPBF may result in the instantiation of porosity defects and variation in build rate. Particularly, volumetric energy density (VED) is a variable that encapsulates a number of those parameters and represents the amount of energy input from the laser source to the feedstock.
View Article and Find Full Text PDFInt J Mol Sci
January 2025
Research Institute for Systems Biology and Medicine (RISBM), Nauchnyi proezd 18, 117246 Moscow, Russia.
SARS-CoV-2 viral entry requires membrane fusion, which is facilitated by the fusion peptides within its spike protein. These predominantly hydrophobic peptides insert into target membranes; however, their precise mechanistic role in membrane fusion remains incompletely understood. Here, we investigate how FP1 (SFIEDLLFNKVTLADAGFIK), the N-terminal fusion peptide, modulates membrane stability and barrier function across various model membrane systems.
View Article and Find Full Text PDFPLoS One
January 2025
Key Laboratory of Tropical Biological Resources of Ministry of Education, School of Pharmaceutical Sciences, Hainan University, Haikou, China.
Electroporation and electrofusion are efficient methods, which have been widely used in different areas of biotechnology and medicine. Pulse strength and width, as an external condition, play an important role in the process of these methods. However, comparatively little work has been done to explore the effects of pulsed electric field parameters on electroporation and electrofusion.
View Article and Find Full Text PDFMethods Mol Biol
January 2025
Department of Immunobiology, University of Lausanne, Epalinges, Switzerland.
Fluorescence recovery after photobleaching (FRAP) can be employed to investigate membrane lipid mixing of vacuoles in live budding yeast cells and distinguish the fused, hemi-fused or non-fused states of these organelles under physiological conditions. Here, we describe a protocol for labeling the outer and inner leaflets of vacuoles in live cells that allow to detect hemifusion intermediates and, thus, identify components necessary for fusion pore opening.
View Article and Find Full Text PDFJ Biomed Mater Res A
January 2025
Faculty of Materials Science and Engineering, Warsaw University of Technology, Warsaw, Poland.
Bone tissue regeneration can be affected by various architectonical features of 3D porous scaffold, for example, pore size and shape, strut size, curvature, or porosity. However, the design of additively manufactured structures studied so far was based on uniform geometrical figures and unit cell structures, which often do not resemble the natural architecture of cancellous bone. Therefore, the aim of this study was to investigate the effect of architectonical features of additively manufactured (aka 3D printed) titanium scaffolds designed based on microtomographic scans of fragments of human femurs of individuals of different ages on in vitro response of human bone-derived mesenchymal stem cells (hMSC).
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