Back to Search
Start Over
Secretion induces cell pH dynamics impacting assembly-disassembly of the fusion protein complex: A combined fluorescence and atomic force microscopy study
- Source :
- Seminars in Cell & Developmental Biology. 73:57-63
- Publication Year :
- 2018
- Publisher :
- Elsevier BV, 2018.
-
Abstract
- A wide range of cellular activities including protein folding and cell secretion, such as neurotransmission or insulin release, are all governed by intracellular pH homeostasis, underscoring the importance of pH on critical life processes. Nano- scale pH measurements of cells and biomolecules therefore hold great promise in understanding a plethora of cellular functions, in addition to disease detection and therapy. In the current study, a novel approach using cadmium telluride quantum dots (CdTeQDs) as pH sensors, combined with fluorescent imaging, spectrofluorimetry, atomic force microscopy (AFM), and Western blot analysis, enabled the study of intracellular pH dynamics at 1 milli-pH sensitivity and 80nm pixel resolution, during insulin secretion. Additionally, the pH-dependent interaction between membrane fusion proteins, also called the soluble N-ethylmaleimide-sensitive factor activating protein receptor (SNARE), was determined. Glucose stimulation of CdTeQD-loaded insulin secreting Min-6 mouse insulinoma cell line demonstrated the initial (5-6min) intracellular acidification reflected as a loss in QD fluorescence, followed by alkalization and a return to resting pH in 10min. Analysis of the SNARE complex in insulin secreting Min-6 cells demonstrated an initial gain followed by loss of complexed SNAREs in 10min. Stabilization of the SNARE complex at low intracellular pH is further supported by results from studies utilizing both native and AFM measurements of liposome-reconstituted recombinant neuronal SNAREs, providing a molecular understanding of the role of pH during cell secretion.
- Subjects :
- 0301 basic medicine
Intracellular pH
Optical Imaging
Lipid bilayer fusion
Cell Biology
Hydrogen-Ion Concentration
Molecular Dynamics Simulation
Biology
Microscopy, Atomic Force
Membrane Fusion
Fusion protein
Fluorescence
Exocytosis
Cell biology
03 medical and health sciences
030104 developmental biology
0302 clinical medicine
Cell culture
Animals
Insulinoma
Protein folding
Secretion
SNARE complex
030217 neurology & neurosurgery
Developmental Biology
Subjects
Details
- ISSN :
- 10849521
- Volume :
- 73
- Database :
- OpenAIRE
- Journal :
- Seminars in Cell & Developmental Biology
- Accession number :
- edsair.doi.dedup.....948a5a4202d65b5364f5854dc62e11ce