NanoBRET™ Target Engagement Intracellular Kinase Assay Nominated for Scientists’ Choice Award®

Joins Nominees for Best New Drug Discovery & Development Product 2017

SelectScience® nominates NanoBRET™ Target Engagement Kinases Assay as a Best New Drug Discovery & Development product for 2017.

We were honored recently to have NanoBRET™ Target Engagement Intracellular Kinase Assays nominated by SelectScience® as one of the Best New Drug Discovery & Development Products of 2017. This is a Scientists’ Choice Award®, an opportunity for scientists like you worldwide to vote for your favorite new drug discovery/development product.

We are super excited about both the nomination and the NanoBRET™ Target Engagement Intracellular Kinase Assay. Here is a little information about the assay.

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Shining Stars: Cool NanoLuc® Plasmid Constructs Available Through the Addgene Repository

Researchers having been sharing plasmids ever since there were plasmids to share. Back when I was in the lab, if you read a paper and saw an interesting construct you wished to use, you could either make it yourself or you could “clone by phone”.  One of my professors was excellent at phone cloning with labs around the world and had specific strategies and tactics for getting the plasmids he wanted. Addgene makes this so much easier to share your constructs from lab to lab. Promega supports the Addgene mission statement: Accelerate research and discovery by improving access to useful research materials and information.  Many of our technology platforms like HaloTag® Fusion Protein, codon-optimized Firefly luciferase genes (e.g., luc2), and NanoLuc® Luciferase are present in the repository. We encourage people to go to Addgene to get new innovative tools. Afterall, isn’t science better when we share?

I’d like to focus on some tools in the Addgene collection based on NanoLuc® Luciferase (NLuc).  The creation of NanoLuc® Luciferase and the optimal substrate furimazine is a good story (1).  From a deep sea shrimp to a compact powerhouse of bioluminescence, NLuc is 100-fold brighter than our more common luciferases like firefly (FLuc) and Renilla (RLuc) luciferase.  This is important not so much for how bright you can make a reaction but for how sensitive you can make a reaction.  NLuc requires 100-fold less protein to produce the same amount of light from a Fluc or RLuc reaction.  NLuc lets you work at physiological concentrations.  NLuc is bright enough to detect endogenous tagged genes generated through the CRISPR/Cas9 knock-in.  NLuc is very inviting for endogenous tagging as it is only 19kDa.  An example is the CRISPaint-NLuc construct (Plasmid #67178) for use in the system outlined in Schmid-Burgk, J.L. et al (2).

Two applications of NanoLuc® Technology have caught my attention through coupling the luciferase with fluorescent proteins to make better imaging reporters and biosensors. Continue reading

Glycosyltransferases: What’s New in GT Assays?

In his 2014 blog, “Why We Care About Glycosyltransferases” Michael Curtin, Promega Global Product Manager for Cell Signaling, wrote:

“Glycobiology is the study of carbohydrates and their role in biology. Glycans, defined as ‘compounds consisting of a large number of monosaccharides linked glycosidically’ are present in all living cells; They coat cell membranes and are integral components of cell walls. They play diverse roles, including critical functions in cell signaling, molecular recognition, immunity and inflammation. They are the cell-surface molecules that define the ABO blood groups and must be taken into consideration to ensure successful blood transfusions.

The process by which a sugar moiety is attached to a biological compound is referred to as glycosylation. Protein glycosylation is a form of post-translational modification, which is important for many biological processes and often serves as an analog switch that modulates protein activity. The class of enzymes responsible for transferring the sugar moiety onto proteins is called a glycosyltransferase (GT).”

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Genes to Cells to Genomes: Where Will Your Research Questions Take You?

Award presentation

Dr. Walter Blum wins trip to Promega headquarters as part of Promega Switzerland’s 25th Anniversary celebration.

Walter Blum knew how normal cells worked. He had studied and read about the pathways that regulated cell cycles, growth and development; he saw the cell as an amazingly well programmed, intricate machine. What he wanted to understand was: “Why does a cell become crazy? How does it escape immune system surveillance?”

Last week I had the opportunity to sit down with Dr. Blum, a customer of our Promega Switzerland branch. Dr. Blum won a trip to visit our campus in Madison for a week as part of an anniversary celebration for our Switzerland branch. While here, he got an inside peek at research and manufacturing operations, chatted with our scientists, met with our marketing teams and saw the sights in Madison. We talked about his work and what he learned and is taking back with him from his trip to Madison. Continue reading

Cytotoxicity Testing of 9,667 Tox21 Compounds using Two Real-Time Assays by Promega

A recent paper in PLOS One demonstrated real-time cytotoxicity profiling of approximately 10,000 chemical compounds in the Tox21 compound library, using two Promega assays, RealTime-Glo™ MT Cell Viability Assay and CellTox™ Green Cytotoxicity Assay. This is exciting to me, a science writer working at Promega; exciting because it’s tricky figuring out how to write about the utility of our products without sounding like an evangelist.

I don’t know about you, but I tend to shut out evangelists and their messages.

Instead of me telling you about real-time viability and cytotoxicity assays from Promega, here is an example of their use in Tox21 chemical compound library research.

What is the Tox21 compound library?
As described in the article by Hsieh, J-H. et al. (2017) in PLOS One:
“The Toxicology in the 21st Century (Tox21) program is a federal collaboration among the National Institutes of Health, including the National Toxicology Program (NTP) at the National Institute of Environmental Health Sciences and the National Center for Advancing Translational Sciences, the Environmental Protection Agency, and the Food and Drug Administration. Tox21 researchers utilize a screening method called high throughput screening (HTS) that uses automated methods to quickly and efficiently test chemicals for activity across a battery of assays that target cellular processes. These assays are useful for rapidly evaluating large numbers of chemicals to provide insight on potential human health effects.” Continue reading

All Aglow in the Ocean Deep

 

Fascinating bioluminescent creature floating on dark waters of the ocean. Polychaete tomopteris.

Today’s blog comes to you from the Promega North America Branch Office.

In nature, the ability to “glow” is actually quite common. Bioluminescence, the chemical reaction involving the molecule luciferin, is a useful adaptation for many lifeforms. Fireflies, mushrooms and creatures of the ocean deep use their internal lightshows to cope with a variety of situations. Used for hunting, communicating, ridding cells of oxygen, and simply surviving in the darkness of the ocean depths, bioluminescence is one of nature’s more flashy, and advantageous traits.

In new research published in April in the journal Scientific Reports, MBARI researchers Séverine Martini and Steve Haddock found that three-quarters of all sea animals make their own light.  The study reviewed 17 years of video from Monterey Bay, Calif in oceans that descended to 2.5 miles, to determine the commonality of bioluminescence in the deep waters.

Martini and Haddock’s observations concluded that 76 percent off all observed animals produced some light, including 97 to 99.7 cnidarians (jellyfish), half of fish, and most polychaetes (worms), cephalopods (squid), and crustaceans (shrimp).

Most of us are familiar with the fabled anglerfish, the menacing deep-sea creature known for attracting ignorant prey with a glowing lure attached to their head. As you descend below 200 meters, where light no longer penetrates, you will be surprised at the unexpected color display of the oceans’ sea life. Bioluminescence is not simply an exotic phenomenon, but an important ecological trait that the oceans’ sea creatures have wholeheartedly adopted to cope with complete darkness. Continue reading

Making BRET the Bright Choice for In vivo Imaging: Use of NanoLuc® Luciferase with Fluorescent Protein Acceptors

13305818-cr-da-nanoluc-application_ligundLive animal in vivo imaging is a common and useful tool for research, but current tools could be better. Two recent papers discuss adaptations of BRET technology combining the brightness of fluorescence with the low background of a bioluminescence reaction to create enhanced in vivo imaging capabilities.

The key is to image photons at wavelengths above 600nm, as lower wavelengths are absorbed by heme-containing proteins (Chu, J., et al., 2016 ). Fluorescent protein use in vivo is limited because the proteins must be excited by an external light source, which generates autofluorescence and has limited penetration due to absorption by tissues. Bioluminescence imaging continues to be a solution, especially firefly luciferase (612nm emission at 37°C), but its use typically requires long image acquisition times. Other luciferases, like NanoLuc, Renilla, and Gaussia, etc. either do not produce enough light or the wavelengths are readily absorbed by tissues, limiting their use to near- surface imaging.

The two papers discussed here illustrate how researchers have combined NanoLuc® luciferase with a fluorescent protein to harness bioluminescent resonance energy transfer (BRET) for brighter in vivo imaging reporters. Continue reading

Don’t Let These Three Common Issues Hurt Your Luminescent Assay Results

4621CAThere is a lot riding on your luminescent assay results. Each plate represents precious time, effort and resources. Did you know that there are three things about your detection instrument that can impact how much useful information you get from each plate?  Instruments with poor sensitivity may cause you to miss low-level samples that could be the “hit” you are looking for.  Instruments with a narrow detection range limit the accuracy or reproducibility you needed to repeat your work.  Finally, instruments that let the signal from bright wells spill into adjacent wells allow crosstalk to occur and skew experimental results, costing you time and leading to failed or repeated experiments. Continue reading

Probing RGS:Gα Protein Interactions with NanoBiT Assays

gpcr_in_membrane_on_white2When I was a post-doc at UT Southwestern, I was fortunate to interact with two Nobel prize winners, Johann Deisenhofer and Fred Gilman.  Johann once helped me move a -80°C freezer into his lab when we lost power in my building. I once replaced my boss at small faculty mixer with a guest speaker and had a drink with Fred Gilman and several other faculty members from around the university. Among the faculty, one professor had a cell phone on his belt, an odd sight in 1995. Fred Gilman asked him what it was and why he had it. It was so his lab could notify him of good results anytime of the day. Fred laughed and told him to get rid of it – if it’s good data, it will survive until morning.

I was reminded of this story when I read a recent paper by Bodle, C.R. et al (1) about the development of a NanoBiT® Complementation Assay (2) to measure interactions of Regulators of G Protein Signaling (RGS) with Gα proteins in cells. (Fred Gilman was the first to isolate a G protein and that led to him being a co-recipient of the Nobel Prize in 1994). The authors created over a dozen NanoBiT Gα:RGS domain pairs and found they could classify different RGS proteins by the speed of the interaction in a cellular context. The interactions were readily reversible with known inhibitors and were suitable for high-throughput screening due to Z’ factors exceeding 0.5. The study paves the way for future work to identify broad spectrum RGS domain:Gα inhibitors and even RGS domain-specific inhibitors. This is the second paper applying NanoBiT Technology to GPCR studies (3).

A Little Background…
A primary function of GPCRs is transmission of extracellular signals across the plasma membrane via coupling with intracellular heterotrimeric G proteins. Upon receptor stimulation, the Gα subunit dissociates from the βγ subunit, initiating the cascade of downstream second messenger pathways that alter transcription (4). The Gα subunits are actually slow GTPases that propagate signals when GTP is bound but shutdown and reassociate with the βγ subunit when GTP is cleaved to GDP. This activation process is known as the GTPase cycle. G proteins are extremely slow GTPases. Continue reading

NanoBiT Assay Applied to Study Role of SOD1 in ALS

NanoBiT Protein ComplementationBack in 2015 the Ice Bucket Challenge brought Amyotrophic Lateral Sclerosis (ALS) to public attention, initiating worldwide pleas for more funding of research toward a cure for this fatal disease, which is characterized by progressive degeneration of motor neurons. In spite of many efforts over the last few decades, the precise cause of ALS is still unknown.

The complexity of the problem of ALS pathogenesis is highlighted in the review “Decoding ALS: from genes to mechanism”  published in Nature in November 2016. The review highlights a long list of genetic factors implicated in ALS, grouping them into genes affecting protein quality control, RNA stability/function, and the cytoskeletal structure of neuronal cells.

Mutations in the antioxidant enzyme superoxide dismutase (SOD1) were the first to be associated with ALS. According to the review, more than 170 SOD1 mutations causing ALS have since been identified. Many of these mutations are thought to result in misfolding of SOD1, contributing to toxicity when the misfolded protein accumulates within the cell.

A paper by Oh-hashi et al., published in Cell Biochemistry and Function in October 2016 used the NanoBiT protein complementation assay to investigate the effect of two common ALS-associated SOD1 mutations on dimerization of the SOD1 protein. Continue reading