Actin cytoskeleton differently regulates cell surface organization of GPI-anchored proteins in polarized epithelial cells and fibroblasts.

The spatiotemporal compartmentalization of membrane-associated glycosylphosphatidylinositol-anchored proteins (GPI-APs) on the cell surface regulates their biological activities. These GPI-APs occupy distinct cellular functions such as enzymes, receptors, and adhesion molecules, and they are implicated in several vital cellular processes. Thus, unraveling the mechanisms and regulators of their membrane organization is essential.

Approaches to monitor ATP levels in living cells: where do we stand?

ATP is the most universal and essential energy molecule in cells. This is due to its ability to store cellular energy in form of high-energy phosphate bonds, which are extremely stable and readily usable by the cell. This energy is key for a variety of biological functions such as cell growth and division, metabolism, and signaling, and for the turnover of biomolecules.

3D quantification of autophagy activation and autophagosome-to-mitochondria recruitment in a model of Parkinson's disease.

Here, we describe a protocol for comprehensive quantification of autophagosome recruitment to mitochondria as an early step in mitophagy. Data collected using this protocol can be useful in the study of neurodegenerative disease, cancer, and metabolism-related disorders using models in which co-expression of mito-GFP and mCherry-Atg8a is feasible. This protocol has the advantage of assessment in an model organism (), where tissue-specific mitophagy can be investigated.

Mitochondrial Aurora kinase A induces mitophagy by interacting with MAP1LC3 and Prohibitin 2.

Epithelial and haematologic tumours often show the overexpression of the serine/threonine kinase AURKA. Recently, AURKA was shown to localise at mitochondria, where it regulates mitochondrial dynamics and ATP production. Here we define the molecular mechanisms of AURKA in regulating mitochondrial turnover by mitophagy.

The NANOTUMOR consortium - Towards the Tumor Cell Atlas.

Cancer is a multi-step disease where an initial tumour progresses through critical steps shaping, in most cases, life-threatening secondary foci called metastases. The oncogenic cascade involves genetic, epigenetic, signalling pathways, intracellular trafficking and/or metabolic alterations within cancer cells. In addition, pre-malignant and malignant cells orchestrate complex and dynamic interactions with non-malignant cells and acellular matricial components or secreted factors within the tumour microenvironment that is instrumental in the progression of the disease.

Real-Time Monitoring of Aurora kinase A Activation using Conformational FRET Biosensors in Live Cells.

Epithelial cancers are often hallmarked by the overexpression of the Ser/Thr kinase Aurora A/AURKA. AURKA is a multifunctional protein that activates upon its autophosphorylation on Thr288. AURKA abundance peaks in mitosis, where it controls the stability and the fidelity of the mitotic spindle, and the overall efficiency of mitosis.

Automated screening of AURKA activity based on a genetically encoded FRET biosensor using fluorescence lifetime imaging microscopy.

Fluorescence Lifetime Imaging Microscopy (FLIM) is a robust tool to measure Förster Resonance Energy Transfer (FRET) between two fluorescent proteins, mainly when using genetically-encoded FRET biosensors. It is then possible to monitor biological processes such as kinase activity with a good spatiotemporal resolution and accuracy. Therefore, it is of interest to improve this methodology for future high content screening purposes.

Insights into the non-mitotic functions of Aurora kinase A: more than just cell division.

AURKA is a serine/threonine kinase overexpressed in several cancers. Originally identified as a protein with multifaceted roles during mitosis, improvements in quantitative microscopy uncovered several non-mitotic roles as well. In physiological conditions, AURKA regulates cilia disassembly, neurite extension, cell motility, DNA replication and senescence programs.

Optimized FRET Pairs and Quantification Approaches To Detect the Activation of Aurora Kinase A at Mitosis.

Genetically encoded Förster's Resonance Energy Transfer (FRET) biosensors are indispensable tools to sense the spatiotemporal dynamics of signal transduction pathways. Investigating the crosstalk between different signaling pathways is becoming increasingly important to follow cell development and fate programs. To this end, FRET biosensors must be optimized to monitor multiple biochemical activities simultaneously and in single cells.