A5025343316- RNA Research and Splicing
- Receptor Mechanisms and Signaling
- Click Chemistry and Applications
- Advanced Fluorescence Microscopy Techniques
- Nicotinic Acetylcholine Receptors Study
- Neuroscience and Neuropharmacology Research
- Genomics and Chromatin Dynamics
- RNA Interference and Gene Delivery
- Tryptophan and brain disorders
- Lipid Membrane Structure and Behavior
- Synthesis and Biological Evaluation
- Ion channel regulation and function
- Signaling Pathways in Disease
- Advanced Electron Microscopy Techniques and Applications
- Photochromic and Fluorescence Chemistry
- Molecular Sensors and Ion Detection
- Advanced Biosensing Techniques and Applications
- Chemical Synthesis and Analysis
- Genetics, Bioinformatics, and Biomedical Research
- Patient Dignity and Privacy
- ATP Synthase and ATPases Research
- Pharmacological Receptor Mechanisms and Effects
- Treatment of Major Depression
- Photodynamic Therapy Research Studies
- Cellular transport and secretion
California Institute of Technology
2017-2025
Convergent Science (United States)
2025
Division of Chemistry
2021-2024
University of Pennsylvania
2013-2018
Oakwood University
2018
Janelia Research Campus
2015-2017
Howard Hughes Medical Institute
2015-2017
Helix (United States)
2016-2017
Transcription factors bind low-affinity DNA sequences for only short durations. It is not clear how brief, interactions can drive efficient transcription. Here, we report that the transcription factor Ultrabithorax (Ubx) utilizes binding sites in Drosophila melanogaster shavenbaby (svb) locus and related enhancers nuclear microenvironments of high Ubx concentrations. Related colocalize to same independently their chromosomal location, suggesting are highly differentiated domains....
The amino acid acridon-2-ylalanine (Acd) can be a valuable probe of protein conformational change because it is long lifetime, visible wavelength fluorophore that small enough to incorporated during ribosomal biosynthesis. Incorporation Acd into proteins expressed in Escherichia coli requires efficient chemical synthesis produce large quantities the and generation mutant aminoacyl tRNA synthetase selectively charge onto tRNA. Here, we report 87% yield over five steps from Tyr identification...
Nicotine dependence is thought to arise in part because nicotine permeates into the endoplasmic reticulum (ER), where it binds nicotinic receptors (nAChRs) and begins an "inside-out" pathway that leads up-regulation of nAChRs on plasma membrane. However, dynamics entry ER are unquantified. Here, we develop a family genetically encoded fluorescent biosensors for nicotine, termed iNicSnFRs. The iNicSnFRs fusions between two proteins: circularly permutated GFP periplasmic...
Nicotinic partial agonists provide an accepted aid for smoking cessation and thus contribute to decreasing tobacco-related disease. Improved drugs constitute a continued area of study. However, there remains no reductionist method examine the cellular subcellular pharmacokinetic properties these compounds in living cells. Here, we developed new intensity-based drug-sensing fluorescent reporters (iDrugSnFRs) nicotinic dianicline, cytisine, two cytisine derivatives – 10-fluorocytisine...
Abstract A minimally invasive “continuous nicotine monitor” (CNM) would resolve the dynamic concentration, [nicotine]t, faced by high-sensitivity nicotinic acetylcholine receptors (nAChRs) during and after intake individual subjects. Motivations: “Know potential enemy at an level”. Smoking or vaping produces initial “bolus” of in blood brain, lasting ~5 min with a peak concentration ~ 100-200 nM. The bolus largely governs reinforcement, reward, cognitive enhancement. prolonged declining...
Selective serotonin reuptake inhibitors (SSRIs) are the most prescribed treatment for individuals experiencing major depressive disorder. The therapeutic mechanisms that take place before, during, or after SSRIs bind transporter (SERT) poorly understood, partially because no studies exist on cellular and subcellular pharmacokinetic properties of in living cells. We studied escitalopram fluoxetine using new intensity-based, drug-sensing fluorescent reporters targeted to plasma membrane,...
Acridonylalanine (Acd) is a useful fluorophore for studying proteins by fluorescence spectroscopy, but it can potentially be improved being made longer wavelength or brighter. Here, we report the synthesis of Acd core derivatives and their photophysical characterization. We also performed ab initio calculations absorption emission spectra derivatives, which agree well with experimental measurements. The amino acid aminoacridonylalanine (Aad) was synthesized in forms appropriate genetic...
The target for the "rapid" (<24 h) antidepressant effects of S-ketamine is unknown, vitiating programs to rationally develop more effective rapid antidepressants. To describe a drug's target, one must first understand compartments entered by drug, at all levels-the organ, cell, and organelle. We have, therefore, developed molecular tools measure subcellular, organellar pharmacokinetics S-ketamine. are genetically encoded intensity-based S-ketamine-sensing fluorescent reporters, iSKetSnFR1...
ABSTRACT Small molecule fluorophores are important tools for advanced imaging experiments. The development of self-labeling protein tags such as the HaloTag and SNAP-tag has expanded utility chemical dyes in live-cell microscopy. We recently described a general method improving brightness photostability small, cell-permeable fluorophores, resulting azetidine-containing “Janelia Fluor” (JF) dyes. Here, we refine extend JF by synthesizing photoactivatable derivatives that compatible with...
We report a reagentless, intensity-based S-methadone fluorescent sensor, iS-methadoneSnFR, consisting of circularly permuted GFP inserted within the sequence mutated bacterial periplasmic binding protein (PBP). evolved previously reported nicotine-binding PBP to become selective S-methadone-binding via three mutations in PBP's second shell and hinge regions. iS-methadoneSnFR displays necessary sensitivity, kinetics, selectivity─notably enantioselectivity against R-methadone─for biological...
Abstract Despite the ongoing epidemic of opioid use disorder and death by fentanyl overdose, opioids remain gold standard for analgesics. Pharmacokinetics (PK) dictates individual’s experience utility drugs; however, PK behavioral outcomes have been conventionally studied in separate groups, even preclinical models. To bridge this gap, we developed first class sensitive, selective, genetically encodable fluorescent biosensors, iOpioidSnFRs, including sensor, iFentanylSnFR. We expressed...
Unnatural amino acids with bioorthogonal reactive groups have the potential to provide a rapid and specific mechanism for covalently inhibiting protein of interest. Here, we use mutagenesis insert an unnatural acid containing azide group (Z) into target at positions such that "click" reaction alkyne modulator (X) will alter function protein. This bioorthogonally pair can engender specificity X Z-containing protein, even if is otherwise identical another allowing validation in living cells....
Abstract Transcription factors regulate gene expression by binding to DNA for short durations and often low-affinity sequences. It is not clear how such temporally brief, interactions can drive efficient transcription. Here we report that the transcription factor Ultrabithorax (Ubx) functionally utilizes sites in Drosophila melanogaster shavenbaby ( svb ) locus nuclear microenvironments of relatively high Ubx concentration. By manipulating affinity enhancers, revealed an inverse relationship...
Subcellular pharmacokinetic measurements have informed the study of central nervous system (CNS)-acting drug mechanisms. Recent investigations been enhanced by use genetically encoded fluorescent biosensors for drugs interest at plasma membrane and in organelles. We describe screening validation protocols identifying hit pairs comprising a biosensor, with each screen including 13-18 candidate 44-84 drugs. After favorable pair is identified validated via these protocols, biosensor then...
A BSTRACT Pushing the frontier of fluorescence microscopy requires design enhanced fluorophores with finely tuned properties. We recently discovered that incorporation four-membered azetidine rings into classic fluorophore structures elicits substantial increases in brightness and photostability, resulting ‘Janelia Fluor’ (JF) series dyes. Here, we refine extend this strategy, showing 3-substituted groups allows rational tuning spectral chemical properties unprecedented precision. This...
ABSTRACT We report a reagentless, intensity-based S-methadone fluorescent sensor, iS-methadoneSnFR, consisting of circularly permuted GFP inserted within the sequence mutated bacterial periplasmic binding protein (PBP). evolved previously reported nicotine-binding PBP to become selective S-methadone-binding via three mutations in PBP’s second shell and hinge regions. iS-methadoneSnFR displays necessary sensitivity, kinetics, selectivity – notably enantioselectivity against R-methadone for...
ABSTRACT Nicotinic partial agonists provide an accepted aid for smoking cessation and thus contribute to decreasing tobacco-related disease. Improved drugs constitute a continued area of study. However, there remains no reductionist method examine the cellular subcellular pharmacokinetic properties these compounds in living cells. Here, we developed new intensity-based drug sensing fluorescent reporters (“iDrugSnFRs”) nicotinic dianicline, cytisine, two cytisine derivatives –...
ABSTRACT Selective serotonin reuptake inhibitors (SSRIs) are the most prescribed treatment for individuals experiencing major depressive disorder (MDD). The therapeutic mechanisms that take place before, during, or after SSRIs bind transporter (SERT) poorly understood, partially because no studies exist of cellular and subcellular pharmacokinetic properties in living cells. We studied escitalopram fluoxetine using new intensity- based drug-sensing fluorescent reporters (“iDrugSnFRs”)...