Search results for " Localization"

Super-resolved linear fluorescence localization microscopy using photostable fluorophores: A virtual microscopy study

2017

Abstract Current approaches to overcome the conventional limit of the resolution potential of light microscopy (of about 200 nm for visible light), often suffer from non-linear effects, which render the quantification of the image intensities in the reconstructions difficult, and also affect the quantification of the biological structure under investigation. As an attempt to face these difficulties, we discuss a particular method of localization microscopy which is based on photostable fluorescent dyes. The proposed method can potentially be implemented as a fast alternative for quantitative localization microscopy, circumventing the need for the acquisition of thousands of image frames and…

Differential subcellular expression of P525LFUS as a putative biomarker for ALS phenoconversion

2020

P525LFused-in-Sarcoma ( FUS ) mutation is associated with a specific amyotrophic lateral sclerosis (ALS) phenotype characterized by a juvenile-onset and a severe course.1 This harmful point mutation is located in the nuclear localization signal (NLS) domain at the protein C-terminal.2 Although wild-type FUS protein is expressed almost exclusively in the nucleus, the P525L FUS mutation leads to a protein mislocalization into the cytoplasm3,4 because of its loss of capacity to bind its transporter karyopherin-2 and to be transferred back to the nucleus.3

Tetraspanin CD63 controls basolateral sorting of organic cation transporter 2 in renal proximal tubules.

2016

CD63 is a ubiquitously expressed member of the tetraspanin superfamily. Using a mating-based split-ubiquitin-yeast 2-hybrid system, pull-down experiments, total internal reflection fluorescence microscopy, Forster resonance energy transfer, and biotinylation assays, we found that CD63 interacts with human organic cation transporter 2 (hOCT2), which transports endogenous and exogenous substrates, such as neurotransmitters and drugs in several epithelial cells. CD63 overexpression affects cellular localization of hOCT2 expressed in human embryonic kidney (HEK)293 cells. Studies with CD63-knockout mice indicate that in renal proximal tubules, CD63 determines the insertion of the mouse ortholog…

2017

Several studies have demonstrated that the expression of odorant receptors (ORs) occurs in various tissues. These findings have served as a basis for functional studies that demonstrate the potential of ORs as drug targets for a clinical application. To the best of our knowledge, this report describes the first evaluation of the mRNA expression of ORs and the localization of OR proteins in the human retina that set a stage for subsequent functional analyses. RNA-Sequencing datasets of three individual neural retinae were generated using Next-generation sequencing and were compared to previously published but reanalyzed datasets of the peripheral and the macular human retina and to reference…

Chimeric proteins tagged with specific 3xHA cassettes may present instability and functional problems

2017

Epitope-tagging of proteins has become a widespread technique for the analysis of protein function, protein interactions and protein localization among others. Tagging of genes by chromosomal integration of PCR amplified cassettes is a widely used and fast method to label proteins in vivo. Different systems have been developed during years in the yeast Saccharomyces cerevisiae. In the present study, we analysed systematically a set of yeast proteins that were fused to different tags. Analysis of the tagged proteins revealed an unexpected general effect on protein level when some specific tagging module was used. This was due in all cases to a destabilization of the proteins and caused a red…

E2F1 interacts with BCL-xL and regulates its subcellular localization dynamics to trigger cell death

2018

International audience; E2F1 is the main pro-apoptotic effector of the pRB-regulated tumor suppressor pathway by promoting the transcription of various pro-apoptotic proteins. We report here that E2F1 partly localizes to mitochondria, where it favors mitochondrial outer membrane permeabilization. E2F1 interacts with BCL-xL independently from its BH3 binding interface and induces a stabilization of BCL-xL at mitochondrial membranes. This prevents efficient control of BCL-xL over its binding partners, in particular over BAK resulting in the induction of cell death. We thus identify a new, non-BH3-binding regulator of BCL-xL localization dynamics that influences its anti-apoptotic activity.

Diversity in AMPA receptor complexes in the brain.

2017

AMPA receptor (AMPAR) complexes comprise four of the AMPAR subunits GluA1-4 and several additional interacting proteins. Subunit composition determines AMPAR function. However, AMPAR function depends to a large extent also on interacting proteins, which influence trafficking to the cell surface, activity-dependent subcellular localization and gating of AMPARs. In this review we report about recent findings on the diversity of AMPAR complexes that allow us to better understand functional properties of native receptors in the brain.

Homer2 and alcohol: A mutual interaction

2017

The past two decades of data derived from addicted individuals and preclinical animal models of addiction implicate a role for the excitatory glutamatergic transmission within the mesolimbic structures in alcoholism. The cellular localization of the glutamatergic receptor subtypes, as well as their signaling efficiency and function, are highly dependent upon discrete functional constituents of the postsynaptic density, including the Homer family of scaffolding proteins. The consequences of repeated alcohol administration on the expression of the Homer family proteins demonstrate a crucial and active role, particularly for the expression of Homer2 isoform, in regulating alcohol-induced behav…

Super-resolution binding activated localization microscopy through reversible change of DNA conformation

2018

ABSTRACT Methods of super-resolving light microscopy (SRM) have found an exponentially growing range of applications in cell biology, including nuclear structure analyses. Recent developments have proven that Single Molecule Localization Microscopy (SMLM), a type of SRM, is particularly useful for enhanced spatial analysis of the cell nucleus due to its highest resolving capability combined with very specific fluorescent labeling. In this commentary we offer a brief review of the latest methodological development in the field of SMLM of chromatin designated DNA Structure Fluctuation Assisted Binding Activated Localization Microscopy (abbreviated as fBALM) as well as its potential future app…

Identification of the Tetraspanin CD9 as an Interaction Partner of Organic Cation Transporters 1 and 2

2019

Organic cation transporters (OCTs) are membrane proteins with relevant physiological (because they accept neurotransmitters as substrate) and pharmacological (because of their interaction with drugs) roles. The human OCTs hOCT1 (SLC22A1/hOCT1) and hOCT2 (SLC22A2/hOCT2) are highly expressed in hepatic (hOCT1) and in renal and neuronal tissue (hOCT2), suggesting a possible role in modulating neurotransmitter activity in the liver, kidney, and brain, and their clearance from the blood. Even though there are several data demonstrating that OCTs are regulated under various patho-physiological conditions, it remains largely unknown which proteins directly interact with OCTs and thereby influence …