Article 7: Henry Colecraft

Stunned by Colecraft’s awareness of the need to “make yourself small,” I realized the resources he draws on to cognitively comprehend the workings of his quarry and simultaneously to grasp the aesthetic and existential tasks of the investigator trespassing onto their field of investigation.  - Rita Charon

Narratives of Discovery

 All non-referenced quotes are the words of Dr. Colecraft

Henry Colecraft lives in the high-stakes nano-world of electrically active cellular messengers that govern the actions of the heart, the brain, the pancreas, the bones, the lungs, and intellectual capacity. Although he has specialized in calcium ion channels, he has evolved a wide and authoritative purview of the whole field of ion channels. Miniscule ion channels on cell membranes control the passage of charged atoms of calcium, potassium, sodium, chloride, and other molecules into cells throughout the body. Each ion channel is made up of intricate protein subunits all of which regulate the rate and amplitude of electrical activity in the whole cell. Unlike neurotransmitters like dopamine and serotonin, that have been touted as the signaling giants in the body and brain and emotions, these membrane signalers do the heroic work of keeping the heart beating, the glucose normal, the pain tolerable, the seizures from starting, the lungs from blocking, and the autism away.

Any number of regulatory proteins—including the RGK group of guanidine-related proteins Ras, Rad, Rem, Rem2, Gem/Ki and the master regulator Calmodulin—augment or inhibit calcium ion fluxes admitted into the cell, whether in the heart, lungs, parathyroid gland, pancreas, peripheral nerves, or the brain.[1],[2] Collectively called voltage-gated calcium ion channels, or Cav,  calcium ion channel fluxes determine cells’ key functions. For example, in the cardiomyocyte, calcium flux mechanisms govern the heartbeat’s excitation/contraction coupling and their timing in cardiomyocytes while the L-type calcium channels found in heart cells’ calveolae participate in the activation of nuclear factor activating T cells (NFAT) to influence gene transcription that modulate chondrogenesis in cardiac valve development.[3] Ion channel functions reveal tremendous scope of both protective and pernicious impact on cells and organisms.

Each of the cardiomyocytes in the human heart can last for 50 years and may or may not be replaceable from progenitor cells. While the myocytes themselves may be long-lived, their ion-channels turn over at a dizzying speed—from  1 to 3 hours seems to be the limit of survival for studied ion channels, and the cytoskeletal microtubule components that guide the ion channels to the plasma membrane have half-lives in the minutes.[3] In skeletal muscle cells and perhaps in cardiomyocytes too, the BAR superfamily of proteins including BIN1 oversees the genesis and movement of T-tubules that deliver ion channels to the plasma membrane to execute calcium influx.[4] Calcium-handling exceeds the membrane-gating of individual calcium-ion channels to include the calcium-sensing receptor (CaSR) which governs the absorption of calcium in the kidney and bone and modulates parathyroid hormone that releases calcium from bones and increases absorption of calcium from the gut and by the kidneys.[5]

Beyond calcium and the heart, cancer biology has identified targets on ion channels for drug intervention to circumvent malignancy-supporting cell conditions and to confer cancer protection.[6]  Colecraft’s discoveries in ion channels redound to the treatment of faulty chloride channels in cystic fibrosis and to reducing neuropathic pain by inhibiting synaptic transmission in sensory neurons.[7]

These cellular phenomena are so incalculably complex that they either had to have been designed by a Zeus atop Mount Olympus—in Plato’s words, Zeus is the "cause of life always to all things"—or so capricious that they had to have come about by random chance.  Chance is the more likely cause, and yet evolutionary change and selection themselves inspire mystery and awe in front of which one bows one’s head. My hyper-compressed summary of ion channel’s actions hints, I hope, at the dramatic spectacle, the complexity of organic entities and phenomena choreographed into a heartbeat. Specialists in ion channels cannot reduce their field of attention to one organ or tissue without sacrificing the whole extraordinary intercalated breath-taking show. They must come away with not only precise and hard-won local knowledge of a particular biological phenomenon but also a wider-than-most vision of the shocking panorama of how the entire organism works.

The ion channels called to Colecraft early in his career as a physiologist and pharmacologist.  I don’t think he himself knows what the siren call was, yet upon finishing his PhD in pharmacology at University of Rochester in 1997, he accepted a post-doc position in the lab of biophysicist and biomedical engineer David Yue at Hopkins. In 2001, he was appointed and remained on the Hopkins faculty until he was recruited to Columbia in 2007.

Now the John C. Dalton Professor  in the Department of Physiology and Cellular Biophysics and Professor in the Department of Molecular Pharmacology and Therapeutics at Columbia University, Dr. Colecraft has achieved both enviable specificity and range. He is at the same time nanoscopically focused on his 160 x 220 Å voltage-gated calcium ion channel in the cardiomyocyte and James-Webb-telescopically situated to view his expansive triadic ambition: to understand what he calls “molecular machines,” to create tools to better study them, and to advance translational work “toward intercepting human misery.” He has advanced impressively on all three of these life goals.

He learned from David Yue the patch-clamp method of gaining access to a single cell and even a single protein within that cell to study electrophysiological events. Colecraft mastered the complex technique to eavesdrop on actual cardiac calcium ion channels as they did their work, zeroing in on the nano-dimensional sub-cellular protein itself that controls the timing and concentration of charged calcium ions traveling into and out of the cardiomyocytes.

Sometimes when we do the patch clamp technique in one configuration, if we are lucky, we'll get a single cell. And a lot of times, if you don't really think about what that means, you can miss certain things. But when someone gets [an ion channel within] a single cell, it doesn't mean that the only thing under that patch is that single [structure in the] cell. Because if you think about the dimensions of it in that experimental configuration, that channel is like a doughnut in a football field. There's a lot of things that can happen in that configuration, in terms of other proteins that are going to be regulating with that channel. And so sometimes it is helpful to make yourself small to, to, to imagine yourself at the scale of the channel.

Stunned by Colecraft’s awareness of the need to “make yourself small,” I realized the resources he draws on to cognitively comprehend the workings of his quarry and simultaneously to grasp the aesthetic and existential tasks of the investigator trespassing onto their field of investigation. Here as throughout our conversations, I was floored by Dr. Colecraft’s visual and metaphorical powers:

Very small. How does that work? Somebody looks at a cell in a microscope: it looks very serene on the surface. It doesn't look like there's much happening at all, but within the cell, it's like a cauldron. There's a lot of different things going on. There are things being taken to different areas. There's power being generated. It, it's like a small town. And then, all those individual proteins are like individual people in that small town and how they interact. And if you don't make yourself small you may not comprehend exactly what's going on. In order to understand what's going on, sometimes you have to get your mind into that scale.

Not unlike “The Incredible Shrinking Man” or Octavia Butler’s speculative fiction, Colecraft’s fantasy of making himself small harnesses the aesthetic recognition of the author’s/artist’s—in this case the scientist’s—physical position as observer vis-à-vis the observed.  He is aware that the scale of his interaction with his quarry matters. More fundamentally, he realizes the salience of his own embodied engagement in the work. When I asked him if he still goes to the lab to watch the mice on the hot plate in the neuropathic pain experiments, for example, he said:

I got into science because I loved, I loved doing the work. I loved it. But now the answer is very little, very little of the work is done in my presence or sight. You're writing the proposals. You are attending meetings. You're on search committees. You're teaching. However, it is important as a PI to keep close to the experiments. When PIs don't do that, they, they lose a sense of, of, of, of reality.

His use of the word “reality”—which my reader can see came after some hesitation—signals his capacity to unblind himself to the dramatic challenges he faces in this work. He may have been referring to the realities of the lab experiments themselves—how long they take, how many retakes are needed. Yet, any investigator, given a good enough problem, reaches a wall of belief in the real world-as-one-knows-it. The brave scientist does not fear crossing the line that delineates what others canonize as real. Quantum mechanics faced that wall when first Grothendieck and then Bohr and Heisenberg  and Einstein asserted that the wave and the particle are coterminous.[8] Others were too loyal to the conventional universe of that time to stray into the unknown of folds and holes in the universe or to imagine traveling on a beam of light. So Henry respects the courage of his predecessors who studied ion movements in biology, no matter how inconclusive their research was during their lifetimes:

I can think about the work of Hodgkin and Huxley who were interested in understanding what was the basis for the electrical activity in neurons. First of all, they had a theory about how this was working. . . . Then, new tools became available for them to be able to actually measure some of these electrical activities. They used the squid giant axon at Woods Hole in Massachusetts. The combination of the theory and the experimentation brought them to this idea that there could be these things called channels. They had no idea what they were in principle or anything.

As others built on that work, it became obvious that there are these things that are called channels. Eventually, in the eighties and nineties, the molecular biology revolution came along and people are now able to go in and find genes that code for these ion channels. You can take them out and put them into a different cell and record a current that wasn't there before. Now most recently, with the cryo-EM revolution, you can actually see these ion channels. So right now seeing is believing and, and, and what arose as a concept in the mind of scientists in the early- and mid-19 hundreds now is something that you can actually see. So it starts as a concept that there must be these kinds of elements present inside the cell. It wasn't knowing whether they were going be a protein or something else, but the idea was borne out. And now we have all these ion channels that we can actually see.

The hypothesis comes first. If the artist’s aesthetic production is the painting or the novel, the scientist’s aesthetic production is not the scientific conclusion. It is the hypothesis. I asked Henry what it takes for the scientist to imagine, like Huxley did, a reality before it can be seen:

Henry’s insistence that imagination is key to good science prompts additional questions: Do we or ought we choose science trainees on the basis of their imaginative powers? Do we or ought we—or can we—lead our graduate students and post-docs toward creativity? Gifted with dexterity in metaphorical thinking and ease in shifting from the key of quantitative evidence to the key of speculation, he comes down on the side of serious play:

One of the things that I do with my grad students is to have brainstorming sessions. Throw out ideas. I think that's the kind of training to [encourage them to] potentially think about things in an imaginative way. I tell them all the time that the greatest part, almost the most important part of this is generating the ideas that are workable, that are new, that are exciting. And then, knowing which idea is going to be really key.

Henry is now moving from the nano to the meta view of voltage-gated biological processes. Pediatrician and geneticist Wendy Chung consulted with Henry on a child with intellectual disability, epilepsy, and ataxia in whom they found a mutation in a calcium channel in the brain. Henry said:

There is absolutely no way to help these people at this stage. And so we are taking a very holistic view of this and doing things from the nano level, which we are good at to using things like stem cells [to come] up with ways to potentially treat these people. It's something that I'm finding really rewarding, hoping that we'll actually be able to make some progress that can make a difference in these people's lives.

But how to get to making a difference in people’s lives? One thing that Henry has focused on in his experimental work is the 76-amino-acid protein ubiquitin, discovered in 1975 and subject of the 2004 Nobel Prize in Chemistry for its role in DNA repair, gene transcription, and targeted protein degradation. With hundreds of associated ligases, proteasomes, and systems of adding to or deleting from other proteins with a network of deubiquitinators, the ubiquitin system controls many traits, including through control or interference in DNA or RNA copying or repair and has been both targeted as cancer treatments and identified as pathological etiologies of some malignancies.

One arm of Henry’s ion channelopathy research selectively de-ubiquitinates ion-channel-specific targets. His team designs, engineers, and introduces deubiquitinases to remove selected ubiquitin chains from mutant ion channels. Once freed from the ubiquitin chains, the tagged ion channels are restored to their normal physiological state and able to function normally, if more slowly than the wild-type protein. The engineered deubiquitinases (enDUBs) cancel the ubiquitin-governed protein degradation. Henry co-founded an innovation company called Stablix to work aggressively on development of small molecules that stabilize proteins by selectively stripping ubiquitin from them. He now sits on the Scientific Advisory Board of the company that is controlled by a group of dedicated scientists who design and execute projects. The approach of selectively removing ubiquitin from target proteins to stabilize proteins has implications for developing medicines for a variety of diseases including rare ion channel diseases such as long QT syndrome and cystic fibrosis, as well as cancers and epilepsy. They learned that one of the lesions in both LQT1 syndrome and cystic fibrosis is faulty trafficking of the molecular ion channel toward the cell membrane due to mutations in the protein:

LQT1 and CF arise from loss-of-function mutations in potassium voltage-gated channel subfamily Q member 1 (KCNQ1) and CF transmembrane regulator (CFTR) channels, respectively. . . . We sought to exploit this shared mechanism to develop a general cell biology approach that would be amenable to therapeutic development and applicable to diverse ion channels. We developed a nanobody-directed deubiquitination approach that enabled selective ubiquitin chain removal from target proteins and rescued the functional expression of mutant ion channels that cause LQT1 and CF. [9] 

This work, Colecraft hopes, may mature toward fulfilling his ambition to add new tools to the bioscientist’s armamentarium in pursuing translational goals in and beyond ion channels:

Beyond therapeutic applications, engineered deubiquitinases (enDUBs) hold tremendous promise as an enabling technology to probe ubiquitin signaling mechanisms in cells. Although great strides have been made in illuminating structural and molecular bases for ubiquitin modifications of proteins in cell-free systems, there is less clarity in elucidating the complex ubiquitin code regulation of individual proteins in living cells. A technical barrier has been the inability to precisely manipulate ubiquitin modifications of particular proteins in situ. enDUBs provide a transformative tool that enables both superior control and adaptability in manipulating the ubiquitin status of target proteins in the complex cellular environment, a development that facilitates a new approach to decipher ubiquitin code regulation of diverse proteins inside cells. [9]

Parallel to his on-going work in deubiquitination, Colecraft’s academic laboratory in the physiology department envisions vaster promises of molecular machinery control. What would happen if investigators could choose among and bioproduce new classes of renewable and recombinant antibodies designed to control variables governing ion channel activity? [10] Colecraft and his collaborator from UC Davis physiologist and membrane biologist James Trimmer critically reviewed the robust field of selective ion channel modulators in foundational investigation of specific ion channel physiology and in therapeutic interventions in disease processes.[11] Both intracellular and extracellular approaches to ion channels modulation are now possible, utilizing intact IgG antibodies and single-chain fragments, single-domain antibody or nanobodies, monoclonal antibodies secreted from hybridoma cells, recombinant monoclonal antibodies and such “designer proteins” as monobodies and intrabodies with capacities for expression in the cytoplasm of mammalian cells. In the therapeutic domains, inducing apoptosis of ion-channel-expressing prostate cancer cells and photoablation of targeted dysfunctional potassium ion channels are among present therapeutic goals. Colecraft and Trimmer note that:

The research community would greatly benefit from a concerted effort to develop a toolbox of widely available renewable recombinant antibodies targeting ion channels. . . . Together a future combining increased availability of renewable recombinant antibodies with . . . emerging techniques for directing their expression and function will open new avenues of ion channel research. [11]

The combination of Henry’s reverence for the pioneers who came before him and his fearless predictions of therapeutically powerful interventions to come potentiate his own contributions to basic science and to translational break-throughs. Underneath both the basic science investigations and the translational science achievements toward clinical gains, Henry senses the societal meanings of the work and the never-resolved mysteries of our universe and individual existence. I quote here from Henry’s obituary on the death of his beloved mentor, David Yue:

David was well known for his eloquence in speech, expressive writing, and vivid figures. David’s deep appreciation of the process of scientific discovery is aptly captured by a quote from a 2006 essay he wrote entitled “The Privilege of Discovery”: “Every so often, the veil of confusing experimental results is parted, and something deep and beautiful about how biological life works is revealed.”[12]

Henry captures the depth and beauty of biological life in his figural language, his metaphorical thought, and his transparent show of wonder and surprise in his scientific writing. He transcends the instrumental levels of scientific exploration to glimpse now and then the astonishment inherent in the work.

I asked Henry about the affectively powerful language in some of his scientific writing—words like “remarkably,” “excitingly,” “promiscuous roles these enzymes play,” and “reassuringly.” I wondered whether he wrote in this affective style to convey to his audiences—scientists and non-scientists—that the author is personally present in the work and some evidence of the tremendous emotional charge that investigators derive from the work itself. He agreed that he was the source of the affective language in a jointly-authored paper as a deep legacy from Yue in his own work:

Okay. It was probably me. . . . I find a great deal of satisfaction from seeing something that is conceived on paper that you just thought about. You imagined it. You put it out on paper. And then you go out and make it happen. When it happens, it's remarkable. I think that's the thing that really keeps us scientists going—that thrill of discovery being the first to come to a new realization. I think it is one of the most rewarding things about the job.

Standing now perhaps midway between his past and his future as a scientist, Henry is poised at the equilibrium between raw curiosity and learned authority. His is the rare and powerful capacity to dream, to fantasize, to elaborate, to spin possibles, and to challenge dogma with new ideas while beholding the magnificence of biology as it has unfolded and the generosity of those who preceded him and created paths toward his own discoveries.