Dynamic Interactions between Autophagosomes and Lipid Droplets in Chlamydomonas reinhardtii.
Quynh-Giao TranHyang Ran YoonKichul ChoSeon-Jin LeeJosé L CrespoRishiram RamananHee-Sik KimPublished in: Cells (2019)
Autophagy is a highly conserved catabolic process in eukaryotic cells by which waste cellular components are recycled to maintain growth in both favorable and stress conditions. Autophagy has been linked to lipid metabolism in microalgae; however, the mechanism underlying this interaction remains unclear. In this study, transgenic Chlamydomonas reinhardtii cells that stably express the red fluorescent protein (mCherry) tagged-ATG8 as an autophagy marker were established. By using this tool, we were able to follow the autophagy process in live microalgal cells under various conditions. Live-cell and transmission electron microscopy (TEM) imaging revealed physical contacts between lipid droplets and autophagic structures during the early stage of nitrogen starvation, while fusion of these two organelles was observed in prolonged nutritional deficiency, suggesting that an autophagy-related pathway might be involved in lipid droplet turnover in this alga. Our results thus shed light on the interplay between autophagy and lipid metabolism in C. reinhardtii, and this autophagy marker would be a valuable asset for further investigations on autophagic processes in microalgae.
Keyphrases
- cell death
- endoplasmic reticulum stress
- induced apoptosis
- cell cycle arrest
- signaling pathway
- oxidative stress
- early stage
- fatty acid
- high resolution
- squamous cell carcinoma
- electron microscopy
- transcription factor
- single cell
- radiation therapy
- high throughput
- risk assessment
- living cells
- protein protein
- photodynamic therapy
- rectal cancer
- amino acid
- label free