The mitogen-activated protein kinase (MAPK) signaling pathway is activated by a number of extra and intracellular stimuli including cytokines, growth factors, and hormones as well as stressors such as oxidative and ER stress. This pathways plays a key role in the regulation of many cellular processes including proliferation, differentiation, the stress response, motility, growth, differentiation, survival, and death. Abnormal MAPK signaling may contribute to increased or uncontrolled cell proliferation and/or resistance to apoptosis. To study this complex pathway, several tools are available, from the pathway specific arrays for an initial screen, to phospho-specific ELISA tests for individual target validation. This post aims at helping you to easily identify tools to explore this pathway in your samples (from arrays to phospho-ELISAs). However, I could not start without showing you once more one of these eye-catching illustrations of cell signalling pathways. I’ll let you explore it to dig out the MAPK protein cascade among all of them (a kind of Where’s Wally for the researcher !).
In a recent paper, Horita H. et al. identified a set of novel Post-Translational Modifications (PTMs) of the protein Programmed Cell Death Ligand (PD-L1).
For this, a novel series of PTM enrichment assays enabling the highly specific profiling of 4 key PTM profiles (Tyrosine phosphorylation (pY), Acetylation (Ac), Unbiquitination (Ub) and SUMOylation 2/3), have been used on EGF-stimulated A431 cell line. They revealed that EGF induced pY, Ac, mono- and poly-Ub Of PD-L1 in these EGF treated epidermoid carcinoma cells. The authors also suggested that the balance between mono- / poly-Ub of PD-L1 might regulate PD-L1 stability, as already described with LDB-1 protein.
These novel PD-L1 PTMs and their related regulatory actions might be valuable information in the future for the design of drug strategies targeting PD-L1/PD-1 immune checkpoint inhibition. [Read more…]
Stauprimide is known to prime Embryonic Stem Cells (ESC) by targeting the c-Myc-activating transcription factor NME2. Its mechanism of action is linked to the inhibition of the nuclear localization of NME2 leading to the downregulation of the transcription of the c-myc oncogene.
In a recent study, Bouvard C. et al. evidenced that Stauprimide’s mechanism of action could also be used to pharmacologically targetc-myc transcription in cancers. [Read more…]
For more than 2 years now, the Silicon Rhodamine-like (SiR) technology has allowed the live cell imaging field with fluorescence microscopy to evolve significantly.
Fluorescent SiR-probes have appeared as the best alternative tools for studying Actin (SiR-actin), Microtubules (SiR-Tubulin), DNA (SiR-DNA) and now lysosome (SiR-Lysosome) for live cell imaging. Who better to show this? Well, here’s how other researchers have been using them to get optimal results. [Read more…]
The HiP™ (High Purity) distinction by BPS Bioscience starts, of course (as the name says), with a high purity level. But that’s not enough. Such pure proteins may aggregate, which is not compatible with binding assays. Thus, the HiP™ label also demands a low level of aggregation, or even none at all. [Read more…]
Progesterone derived Allopregnanolone (ALLO) is an extensively studied neurosteroid that has been shown to be involved in neurodegenerative diseases, including Alzheimer’s, Parkinson’s disease, and multiple sclerosis. It is also linked to neuroinflammatory processes through a beneficial action on pro-inflammatory cytokines.
Allopregnanolone detection kits based on polyclonal antibodies were already available through Arbor Assays (K044-H and K044-C), a specialist of immunassay kits, with a special focus on inflammation and reproduction targets.
A new Allopregnanolone EIA kit has just been released, based on a monoclonal antibody (K061-H1). In addition to the supply stability offered by the monoclonal antibodies, this new kit is more sensitive than the original one, it requires smaller sample volumes and provides increased signal. It also has a more favorable cross reactivity profile: [Read more…]
The JAK/STAT pathway is an important signalling process for numerous cytokines and growth factors.
Its activation is essential to many processes such as hematopoiesis, immune development, growth, adipogenesis, mammary gland development… [Read more…]
PD-1 / NFAT Reporter – Jurkat Cell Line
The PD-1 reporter cell line is a T cell line expressing luciferase under the control of NFAT response elements. The level of the luciferase activity measured with the One-Step luciferase detection system (BPS Bioscience) corresponds to the T cell activation in response to the TCR activator from the target cell.
To escape, the target cell may present PD-L1 or PD-L2 to PD-1. Indeed, the interaction inhibits the T cell activation. It leads to decrease in luciferase activity. [Read more…]
Reactive oxygen species (ROS) play key roles in various intracellular processes and have been shown to be involved in many diseases (eg. carcinogenesis, inflammation…). Each of the ROS species is likely to have a specific role in living cells. Therefore, there is an emerging need for selectively detecting each species of ROS through conventional biochemical assays, but also in live cell imaging (see a previous post “Reactive Oxygen Species (ROS) and related assay kits“).
Luciferase is the general term given to a class of oxidative enzymes that catalyze reactions that give off light, a process known as bio-luminescence (Fig. 1). In biology, researchers can take advantage of this reaction and use it as a readout for various biological processes. This has perhaps been exploited most in luciferase reporter cell lines where a promoter region from a gene of interest is placed immediately upstream of the coding sequence for luciferase. In this system, transcriptional activation of the gene of interest leads to a level of luciferase expression that is proportional to the level of gene activation.