Nobel Prize
The Chemistry Clicked: Two NIH-Supported Researchers Win 2022 Nobel Prize in Chemistry
Posted on by Lawrence Tabak, D.D.S., Ph.D.
Through the years, NIH has supported a total of 169 researchers who have received or shared 101 Nobel Prizes. That’s quite a testament to the world-leading science that NIH pursues and its continued impact on improving human health and well-being.
Those numbers include the news late last week that the 2022 Nobel Prize in Chemistry was shared by two long-time grantees for their work on a transformative scientific approach known as “click chemistry.” This form of chemistry has made it possible for researchers to snap together, like LEGO pieces, molecular building blocks to form hybrid biomolecules, often with easy-to-track imaging agents attached. Not only has click chemistry expanded our ability to explore the molecular underpinnings of a wide range of biological processes, but it has provided us with new tools for developing drugs, diagnostics, and a wide array of “smart” materials.
For K. Barry Sharpless, Scripps Research, La Jolla, CA, October 5, 2022 marked the second time that he’s received an early-morning congratulatory call from The Royal Swedish Academy of Sciences. The first such call came in 2001, when Sharpless got the news that he was a co-winner of the Nobel Prize in Chemistry for his discovery of asymmetric catalytic reactions.
This time around, Sharpless was recognized for his groundbreaking studies in the mid-1990s with click chemistry, a term that he coined himself. His initial work established click chemistry as a fast-and-reliable way to attach molecules of interest in the lab [1]. He and co-recipient Morten Meldal, University of Copenhagen, Denmark, who is not funded by NIH, then independently introduced a copper-catalyzed click that further refined the chemistry and helped popularize it across biology and the material sciences [2,3].
For Carolyn R. Bertozzi of Stanford University, Palo Alto, CA, it is her first Nobel. Bertozzi was recognized for expanding the use of click chemistry with so-called bioorthogonal chemistry, which is a copper-free version of the approach that can be used inside living cells without the risk of metal-associated toxicities [4,5].
Bertozzi’s work has been especially interesting to me because of her focus on glycans, which I’ve studied throughout my career. Glycans are the carbohydrate molecules that coat the surfaces of our cells and most secreted proteins. They are essential to life, and, in higher organisms, play fundamental roles in basic processes such as metabolism, immunity, and cellular communication.
Glycans also remain poorly understood, largely because, until recently, they have been so difficult for basic scientists to study with traditional techniques. That has changed with development of new tools to study glycans and the enzymes that assemble them. My long-time collaborator, Kelly Ten Hagen, a senior investigator at NIH’s National Institute of Dental and Craniofacial Research, and I collaborated with Carolyn on identifying small molecules that inhibit the enzyme responsible for the first step in mucin-type O-glycosylation [6]
In the early 2000s, Bertozzi and her team introduced bioorthogonal chemistry, which enabled researchers to label glycans and visualize them in a range of cells and living organisms. Her team’s pioneering approach quickly became an essential tool in basic science labs around the world that study glycans, leading to a number of stunning discoveries that would have otherwise been difficult or impossible.
For clinical researchers, click chemistry has emerged as a workhorse in drug discovery and the improved targeting of cancer chemotherapies and other small-molecule drugs. The approach also is being used to improve delivery of antibody-based therapies and to create new biomaterials. Meanwhile, in the material sciences, click chemistry has been used to solve a number of problems in working with polymers and to expand their industrial uses.
Click chemistry is an excellent example of how advances in basic science can build the foundation for a wide range of practical applications, including those aimed at improving human health. It also highlights the value of strong, sustained public funding for fundamental research, and NIH is proud to have supported Sharpless continuously since 1975 and Bertozzi since 1999. I send my sincere congratulations to both of these most-deserving scientists.
References:
[1] Click Chemistry: Diverse chemical function from a few good reactions. Kolb, HC, Finn, MG, Sharpless, KB. Angew. Chem. Int. Ed. 2001, 40 (11), 2004–2021
[2] A stepwise huisgen cycloaddition process: Copper(I)-catalyzed regioselective “Llgation” of azides and terminal alkynes. Rostovtsev VV, Green LG, Fokin VV, Sharpless KB. Angew. Chem. Int. Ed. 2002, 41 (14), 2596–2599.
[3] Peptidotriazoles on solid phase: [1,2,3]-Triazoles by regiospecific copper(I)-catalyzed 1,3-dipolar cycloadditions of terminal alkynes to azides. Tornøe CW, Sengeløv H, Meldal M. J. Org. Chem. 2002, 67 (9), 3057–3064.
[4] A strain-promoted [3 + 2] azide−alkyne cycloaddition for covalent modification of biomolecules in living systems. Agard NJ, Prescher JA, Bertozzi CR. J. Am. Chem. Soc. 2004, 126 (46), 15046–15047
[5] In vivo imaging of membrane associated glycans in developing zebrafish. Laughlin ST, Baskin JM, Amacher SL, Bertozzi CR. Science 2008, 320 (5876), 664–667.
[6] Small molecule inhibitors of mucin-type O-glycosylation from a uridine-based library. Hang, HC, Yu, C, Ten Hagen, KG, Tian, E, Winans, KA, Tabak, LA, Bertozzi, Chem Biol. 2004 Jul;11(7):1009-1016.
Links:
The Nobel Prize in Chemistry 2022 (The Royal Swedish Academy of Sciences, Stockholm)
Video: Announcement of the 2022 Nobel Prize in Chemistry (YouTube)
Click Chemistry and Bioorthogonal Chemistry (The Royal Swedish Academy of Sciences)
Sharpless Lab (Scripps Research, La Jolla, CA)
Bertozzi Group (Stanford University, Palo Alto, CA)
NIH Support:
K. Barry Sharpless: National Institute of General Medical Sciences
Carolyn R. Bertozzi: National Cancer Institute; National Institute of Allergy and Infectious Diseases; National Institute of General Medical Sciences
NIH’s Nobel Winners Demonstrate Value of Basic Research
Posted on by Dr. Francis Collins
Last week was a big one for both NIH and me. Not only did I announce my plans to step down as NIH Director by year’s end to return to my lab full-time, I was reminded by the announcement of the 2021 Nobel Prizes of what an honor it is to be affiliated an institution with such a strong, sustained commitment to supporting basic science.
This year, NIH’s Nobel excitement started in the early morning hours of October 4, when two NIH-supported neuroscientists in California received word from Sweden that they had won the Nobel Prize in Physiology or Medicine. One “wake up” call went to David Julius, University of California, San Francisco (UCSF), who was recognized for his groundbreaking discovery of the first protein receptor that controls thermosensation, the body’s perception of temperature. The other went to his long-time collaborator, Ardem Patapoutian, Scripps Research Institute, La Jolla, CA, for his seminal work that identified the first protein receptor that controls our sense of touch.
But the good news didn’t stop there. On October 6, the 2021 Nobel Prize in Chemistry was awarded to NIH-funded chemist David W.C. MacMillan of Princeton University, N.J., who shared the honor with Benjamin List of Germany’s Max Planck Institute. (List also received NIH support early in his career.)
The two researchers were recognized for developing an ingenious tool that enables the cost-efficient construction of “greener” molecules with broad applications across science and industry—including for drug design and development.
Then, to turn this into a true 2021 Nobel Prize “hat trick” for NIH, we learned on October 12 that two of this year’s three Nobel winners in Economic Sciences had been funded by NIH. David Card, an NIH-supported researcher at University of California, Berkley, was recognized “for his empirical contributions to labor economics.” He shared the 2021 prize with NIH grantee Joshua Angrist of Massachusetts Institute of Technology, Cambridge, and his colleague Guido Imbens of Stanford University, Palo Alto, CA, “for their methodological contributions to the analysis of causal relationships.” What a year!
The achievements of these and NIH’s 163 past Nobel Prize winners stand as a testament to the importance of our agency’s long and robust history of investing in basic biomedical research. In this area of research, scientists ask fundamental questions about how life works. The answers they uncover help us to understand the principles, mechanisms, and processes that underlie living organisms, including the human body in sickness and health.
What’s more, each advance builds upon past discoveries, often in unexpected ways and sometimes taking years or even decades before they can be translated into practical results. Recent examples of life-saving breakthroughs that have been built upon years of fundamental biomedical research include the mRNA vaccines for COVID-19 and the immunotherapy approaches now helping people with many types of cancer.
Take the case of the latest Nobels. Fundamental questions about how the human body responds to medicinal plants were the initial inspiration behind the work of UCSF’s Julius. He’d noticed that studies from Hungary found that a natural chemical in chili peppers, called capsaicin, activated a subgroup of neurons to create the painful, burning sensation that most of us have encountered from having a bit too much hot sauce. But what wasn’t known was the molecular mechanism by which capsaicin triggered that sensation.
In 1997, having settled on the best experimental approach to study this question, Julius and colleagues screened millions of DNA fragments corresponding to genes expressed in the sensory neurons that were known to interact with capsaicin. In a matter of weeks, they had pinpointed the gene encoding the protein receptor through which capsaicin interacts with those neurons [1]. Julius and team then determined in follow-up studies that the receptor, later named TRPV1, also acts as a thermal sensor on certain neurons in the peripheral nervous system. When capsaicin raises the temperature to a painful range, the receptor opens a pore-like ion channel in the neuron that then transmit a signal for the unpleasant sensation on to the brain.
In collaboration with Patapoutian, Julius then turned his attention from hot to cold. The two used the chilling sensation of the active chemical in mint, menthol, to identify a protein called TRPM8, the first receptor that senses cold [2, 3]. Additional pore-like channels related to TRPV1 and TRPM8 were identified and found to be activated by a range of different temperatures.
Taken together, these breakthrough discoveries have opened the door for researchers around the world to study in greater detail how our nervous system detects the often-painful stimuli of hot and cold. Such information may well prove valuable in the ongoing quest to develop new, non-addictive treatments for pain. The NIH is actively pursuing some of those avenues through its Helping to End Addiction Long-termSM (HEAL) Initiative.
Meanwhile, Patapoutian was busy cracking the molecular basis of another basic sense: touch. First, Patapoutian and his collaborators identified a mouse cell line that produced a measurable electric signal when individual cells were poked. They had a hunch that the electrical signal was generated by a protein receptor that was activated by physical pressure, but they still had to identify the receptor and the gene that coded for it. The team screened 71 candidate genes with no luck. Then, on their 72nd try, they identified a touch receptor-coding gene, which they named Piezo1, after the Greek word for pressure [4].
Patapoutian’s group has since found other Piezo receptors. As often happens in basic research, their findings have taken them in directions they never imagined. For example, they have discovered that Piezo receptors are involved in controlling blood pressure and sensing whether the bladder is full. Fascinatingly, these receptors also seem to play a role in controlling iron levels in red blood cells, as well as controlling the actions of certain white blood cells, called macrophages.
Turning now to the 2021 Nobel in Chemistry, the basic research of MacMillan and List has paved the way for addressing a major unmet need in science and industry: the need for less expensive and more environmentally friendly catalysts. And just what is a catalyst? To build the synthetic molecules used in drugs and a wide range of other materials, chemists rely on catalysts, which are substances that control and accelerate chemical reactions without becoming part of the final product.
It was long thought there were only two major categories of catalysts for organic synthesis: metals and enzymes. But enzymes are large, complex proteins that are hard to scale to industrial processes. And metal catalysts have the potential to be toxic to workers, as well as harmful to the environment. Then, about 20 years ago, List and MacMillan, working independently from each other, created a third type of catalyst. This approach, known as asymmetric organocatalysis [5, 6], builds upon small organic molecule catalysts that have a stable framework of carbon atoms, to which more active chemical groups can attach, often including oxygen, nitrogen, sulfur, or phosphorus.
Organocatalysts have gone on to be applied in ways that have proven to be more cost effective and environmentally friendly than using traditional metal or enzyme catalysts. In fact, this precise new tool for molecular construction is now being used to build everything from new pharmaceuticals to light-absorbing molecules used in solar cells.
That brings us to the Nobel Prize in the Economic Sciences. This year’s laureates showed that it’s possible to reach cause-and-effect answers to questions in the social sciences. The key is to evaluate situations in groups of people being treated differently, much like the design of clinical trials in medicine. Using this “natural experiment” approach in the early 1990s, David Card produced novel economic analyses, showing an increase in the minimum wage does not necessarily lead to fewer jobs. In the mid-1990s, Angrist and Imbens then refined the methodology of this approach, showing that precise conclusions can be drawn from natural experiments that establish cause and effect.
Last year, NIH added the names of three scientists to its illustrious roster of Nobel laureates. This year, five more names have been added. Many more will undoubtedly be added in the years and decades ahead. As I’ve said many times over the past 12 years, it’s an extraordinary time to be a biomedical researcher. As I prepare to step down as the Director of this amazing institution, I can assure you that NIH’s future has never been brighter.
References:
[1] The capsaicin receptor: a heat-activated ion channel in the pain pathway. Caterina MJ, Schumacher MA, Tominaga M, Rosen TA, Levine JD, Julius D. Nature 1997:389:816-824.
[2] Identification of a cold receptor reveals a general role for TRP channels in thermosensation. McKemy DD, Neuhausser WM, Julius D. Nature 2002:416:52-58.
[3] A TRP channel that senses cold stimuli and menthol. Peier AM, Moqrich A, Hergarden AC, Reeve AJ, Andersson DA, Story GM, Earley TJ, Dragoni I, McIntyre P, Bevan S, Patapoutian A. Cell 2002:108:705-715.
[4] Piezo1 and Piezo2 are essential components of distinct mechanically activated cation channels. Coste B, Mathur J, Schmidt M, Earley TJ, Ranade S, Petrus MJ, Dubin AE, Patapoutian A. Science 2010:330: 55-60.
[5] Proline-catalyzed direct asymmetric aldol reactions. List B, Lerner RA, Barbas CF. J. Am. Chem. Soc. 122, 2395–2396 (2000).
[6] New strategies for organic catalysis: the first highly enantioselective organocatalytic Diels-AlderReaction. Ahrendt KA, Borths JC, MacMillan DW. J. Am. Chem. Soc. 2000, 122, 4243-4244.
Links:
Basic Research – Digital Media Kit (NIH)
Curiosity Creates Cures: The Value and Impact of Basic Research (National Institute of General Medical Sciences/NIH)
Explaining How Research Works (NIH)
NIH Basics, Collins FS, Science, 3 Aug 2012. 337; 6094: 503.
NIH’s Commitment to Basic Science, Mike Lauer, Open Mike Blog, March 25, 2016
Nobel Laureates (NIH)
The Nobel Prize in Physiology or Medicine 2021 (The Nobel Assembly at the Karolinska Institutet, Stockholm, Sweden)
Video: Announcement of the 2021 Nobel Prize in Physiology or Medicine (YouTube)
The Nobel Prize in Chemistry 2021 (The Nobel Assembly at the Karolinska Institutet)
Video: Announcement of the 2021 Nobel Prize in Chemistry (YouTube)
The Nobel Prize in Economic Sciences (The Nobel Assembly at the Karolinska Institutet)
Video: Announcement of the 2021 Nobel Prize in Economic Sciences (YouTube)
Julius Lab (University of California San Francisco)
The Patapoutian Lab (Scripps Research, La Jolla, CA)
Benjamin List (Max-Planck-Institut für Kohlenforschung, Mülheim an der Ruhr, Germany)
The MacMillan Group (Princeton University, NJ)
David Card (University of California, Berkeley)
Joshua Angrist (Massachusetts Institute of Technology, Cambridge)
NIH Support:
David Julius: National Institute of Neurological Diseases and Stroke; National Institute of General Medical Sciences; National Institute of Dental and Craniofacial Research
Ardem Patapoutian: National Institute of Neurological Diseases and Stroke; National Institute of Dental and Craniofacial Research; National Heart, Lung, and Blood Institute
David W.C. MacMillan: National Institute of General Medical Sciences
David Card: National Institute on Aging; Eunice Kennedy Shriver National Institute of Child Health and Human Development
Joshua Angrist: Eunice Kennedy Shriver National Institute of Child Health and Human Development
Ceremonial Nobel Presentation
Posted on by Dr. Francis Collins
The Perfect Cytoskeletal Storm
Posted on by Dr. Francis Collins
Ever thought about giving cell biology a whirl? If so, I suggest you sit down and take a look at this full-blown cytoskeletal “storm,” which provides a spectacular dynamic view of the choreography of life.
Before a cell divides, it undergoes a process called mitosis that copies its chromosomes and produces two identical nuclei. As part of this process, microtubules, which are structural proteins that help make up the cell’s cytoskeleton, reorganize the newly copied chromosomes into a dense, football-shaped spindle. The position of this mitotic spindle tells the cell where to divide, allowing each daughter cell to contain its own identical set of DNA.
To gain a more detailed view of microtubules in action, researchers designed an experimental system that utilizes an extract of cells from the African clawed frog (Xenopus laevis). As the video begins, a star-like array of microtubules (red) radiate outward in an apparent effort to prepare for cell division. In this configuration, the microtubules continually adjust their lengths with the help of the protein EB-1 (green) at their tips. As the microtubules grow and bump into the walls of a lab-generated, jelly-textured enclosure (dark outline), they buckle—and the whole array then whirls around the center.
Abdullah Bashar Sami, a Ph.D. student in the NIH-supported lab of Jesse “Jay” Gatlin, University of Wyoming, Laramie, shot this movie as a part his basic research to explore the still poorly understood physical forces generated by microtubules. The movie won first place in the 2019 Green Fluorescent Protein Image and Video Contest sponsored by the American Society for Cell Biology. The contest honors the 25th anniversary of the discovery of green fluorescent protein (GFP), which transformed cell biology and earned the 2008 Nobel Prize in Chemistry for three scientists who had been supported by NIH.
Like many movies, the setting was key to this video’s success. The video was shot inside a microfluidic chamber, designed in the Gatlin lab, to study the physics of microtubule assembly just before cells divide. The tiny chamber holds a liquid droplet filled with the cell extract.
When the liquid is exposed to an ultra-thin beam of light, it forms a jelly-textured wall, which traps the molecular contents inside [1]. Then, using time-lapse microscopy, the researchers watch the mechanical behavior of GFP-labeled microtubules [2] to see how they work to position the mitotic spindle. To do this, microtubules act like shapeshifters—scaling to adjust to differences in cell size and geometry.
The Gatlin lab is continuing to use their X. laevis system to ask fundamental questions about microtubule assembly. For many decades, both GFP and this amphibian model have provided cell biologists with important insights into the choreography of life, and, as this work shows, we can expect much more to come!
References:
[1] Microtubule growth rates are sensitive to global and local changes in microtubule plus-end density. Geisterfer ZM, Zhu D, Mitchison T, Oakey J, Gatlin JC. November 20, 2019.
[2] Tau-based fluorescent protein fusions to visualize microtubules. Mooney P, Sulerud T, Pelletier JF, Dilsaver MR, et al. Cytoskeleton (Hoboken). 2017 Jun;74(6):221-232.
Links:
Mitosis (National Human Genome Research Institute/NIH)
Gatlin Lab (University of Wyoming, Laramie)
Green Fluorescent Protein Image and Video Contest (American Society for Cell Biology, Bethesda, MD)
2008 Nobel Prize in Chemistry (Nobel Foundation, Stockholm, Sweden)
NIH Support: National Institute of General Medical Sciences
Seeing the Cytoskeleton in a Whole New Light
Posted on by Dr. Francis Collins
It’s been 25 years since researchers coaxed a bacterium to synthesize an unusual jellyfish protein that fluoresced bright green when irradiated with blue light. Within months, another group had also fused this small green fluorescent protein (GFP) to larger proteins to make their whereabouts inside the cell come to light—like never before.
To mark the anniversary of this Nobel Prize-winning work and show off the rainbow of color that is now being used to illuminate the inner workings of the cell, the American Society for Cell Biology (ASCB) recently held its Green Fluorescent Protein Image and Video Contest. Over the next few months, my blog will feature some of the most eye-catching entries—starting with this video that will remind those who grew up in the 1980s of those plasma balls that, when touched, light up with a simulated bolt of colorful lightning.
This video, which took third place in the ASCB contest, shows the cytoskeleton of a frequently studied human breast cancer cell line. The cytoskeleton is made from protein structures called microtubules, made visible by fluorescently tagging a protein called doublecortin (orange). Filaments of another protein called actin (purple) are seen here as the fine meshwork in the cell periphery.
The cytoskeleton plays an important role in giving cells shape and structure. But it also allows a cell to move and divide. Indeed, the motion in this video shows that the complex network of cytoskeletal components is constantly being organized and reorganized in ways that researchers are still working hard to understand.
Jeffrey van Haren, Erasmus University Medical Center, Rotterdam, the Netherlands, shot this video using the tools of fluorescence microscopy when he was a postdoctoral researcher in the NIH-funded lab of Torsten Wittman, University of California, San Francisco.
All good movies have unusual plot twists, and that’s truly the case here. Though the researchers are using a breast cancer cell line, their primary interest is in the doublecortin protein, which is normally found in association with microtubules in the developing brain. In fact, in people with mutations in the gene that encodes this protein, neurons fail to migrate properly during development. The resulting condition, called lissencephaly, leads to epilepsy, cognitive disability, and other neurological problems.
Cancer cells don’t usually express doublecortin. But, in some of their initial studies, the Wittman team thought it would be much easier to visualize and study doublecortin in the cancer cells. And so, the researchers tagged doublecortin with an orange fluorescent protein, engineered its expression in the breast cancer cells, and van Haren started taking pictures.
This movie and others helped lead to the intriguing discovery that doublecortin binds to microtubules in some places and not others [1]. It appears to do so based on the ability to recognize and bind to certain microtubule geometries. The researchers have since moved on to studies in cultured neurons.
This video is certainly a good example of the illuminating power of fluorescent proteins: enabling us to see cells and their cytoskeletons as incredibly dynamic, constantly moving entities. And, if you’d like to see much more where this came from, consider visiting van Haren’s Twitter gallery of microtubule videos here:
Reference:
[1] Doublecortin is excluded from growing microtubule ends and recognizes the GDP-microtubule lattice. Ettinger A, van Haren J, Ribeiro SA, Wittmann T. Curr Biol. 2016 Jun 20;26(12):1549-1555.
Links:
Lissencephaly Information Page (National Institute of Neurological Disorders and Stroke/NIH)
Wittman Lab (University of California, San Francisco)
Green Fluorescent Protein Image and Video Contest (American Society for Cell Biology, Bethesda, MD)
NIH Support: National Institute of General Medical Sciences
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