A5101731819- Advanced Fluorescence Microscopy Techniques
- Parathyroid Disorders and Treatments
- Magnesium in Health and Disease
- Ion Transport and Channel Regulation
- Advancements in Transdermal Drug Delivery
- Photorefractive and Nonlinear Optics
- Advanced Optical Imaging Technologies
- Lipid Membrane Structure and Behavior
- Optical Coherence Tomography Applications
- Wound Healing and Treatments
- Potassium and Related Disorders
- Photoacoustic and Ultrasonic Imaging
- Dermatology and Skin Diseases
- Molecular Biology Techniques and Applications
- Neonatal skin health care
- Erythrocyte Function and Pathophysiology
- Laser-Matter Interactions and Applications
- Micro and Nano Robotics
- RNA and protein synthesis mechanisms
- Ocular and Laser Science Research
- Photonic and Optical Devices
- Solid State Laser Technologies
- Advanced Optical Sensing Technologies
- Photoreceptor and optogenetics research
- Optical Imaging and Spectroscopy Techniques
MRC Laboratory of Molecular Biology
2010-2018
Medical Research Council
2010-2016
McGovern Institute for Brain Research
2016
University College Dublin
2011
University of Colorado Health
2004-2010
University of Colorado Denver
2004-2010
University of Colorado Hospital
2004-2010
University of Colorado Anschutz Medical Campus
2004
University of Illinois Urbana-Champaign
2001-2004
Imperial College London
1995-1998
Protein phosphorylation regulates virtually all biological processes. Although protein kinases are popular drug targets, targeting phosphatases remains a challenge. Here, we describe Sephin1 (selective inhibitor of holophosphatase), small molecule that safely and selectively inhibited regulatory subunit phosphatase 1 in vivo. bound the stress-induced PPP1R15A, but not related constitutive PPP1R15B, to prolong benefit an adaptive phospho-signaling pathway, protecting cells from otherwise...
Methods to site-specifically and densely label proteins in cellular ultrastructures with small, bright, photostable fluorophores would substantially advance super-resolution imaging. Recent advances genetic code expansion bioorthogonal chemistry have enabled the site-specific labeling of proteins. However, efficient incorporation unnatural amino acids into specific, fluorescent intracellular they form for subdiffraction imaging has not been accomplished. Two challenges limited progress this...
The outermost epidermal layer, the stratum corneum (SC), exhibits an acidic surface pH, whereas pH at its base approaches neutrality. NHE1 is only Na(+)/H(+) antiporter isoform in keratinocytes and epidermis, has been shown to regulate intracellular pH. We now demonstrate a novel function for NHE1, as we find that it also controls acidification of extracellular "microdomains" SC are essential activation pH-sensitive enzymes formation permeability barrier. expression epidermis most pronounced...
Hyperphosphatemia associated with chronic kidney disease is one of the factors that can promote vascular calcification, and intestinal P(i) absorption pharmacological targets prevents it. The type II Na-P(i) cotransporter NaPi-2b major transporter mediates reabsorption in intestine. potential role regulation other transporters remain unknown. We have identified expression III PiT-1 apical membrane enterocytes. transport activity proteins are mostly expressed duodenum jejunum rat small...
The Wnt signaling pathway is critical in normal development, and mutation of specific components frequently observed carcinomas diverse origins. However, the potential involvement this lung tumorigenesis has not been established. In study, analysis multiple mRNAs non-small cell cancer (NSCLC) lines primary tumors revealed markedly decreased Wnt-7a expression compared with short-term bronchial epithelial uninvolved tissue. transfection NSCLC reversed cellular transformation,...
Animal cells migrating over a substratum crawl in amoeboid fashion; how the force against is achieved remains uncertain. We find that amoebae and neutrophils, traditionally used to study cell migration on solid surface, move toward chemotactic source while suspended solution. They can swim do so with speeds similar those substrate. Based surprisingly rapidly changing shape of as they earlier theoretical schemes for microorganisms migrate (Purcell EM (1977) Life at low Reynolds number. Am J...
Two-photon excitation fluorescence microscopy allows in vivo high-resolution imaging of human skin structure and biochemistry with a penetration depth over 100 µm. The major damage mechanism during two-photon is associated the formation cavitation at epidermal-dermal junction, which results thermal mechanical tissue. In this report, we verify that origin one-photon absorption infrared light by melanin granules present junction. threshold for selected Caucasian specimens from bank as function...
Dietary potassium (K) deficiency is accompanied by phosphaturia and decreased renal brush border membrane (BBM) vesicle sodium (Na)-dependent phosphate (P i ) transport activity. Our laboratory previously showed that K in rats leads to increased abundance the proximal tubule BBM of apical Na-P cotransporter NaPi-IIa, but activity, diffusion, clustering NaPi-IIa could be modulated altered lipid composition K-deficient (Zajicek HK, Wang H, Puttaparthi K, Halaihel N, Markovich D, Shayman J,...
We characterized several cellular and structural features of early stage Type II/III atherosclerotic plaques in an established model atherosclerosis-the ApoE-deficient mouse-by using a multimodal, coregistered imaging system that integrates three nonlinear optical microscopy (NLOM) contrast mechanisms: coherent anti-Stokes Raman scattering (CARS), second harmonic generation (SHG), two-photon excitation fluorescence (TPEF). Specifically, the infiltration lipid-rich macrophages organization...
Parathyroid hormone (PTH) plays a critical role in the regulation of renal phosphorous homeostasis by altering levels sodium-phosphate cotransporter NaPi2a brush border membrane (BBM) proximal tubular cells. While details molecular events PTH-induced internalization are emerging, precise governing removal from microvilli response to PTH remain be fully determined. Here we use novel application total internal reflection fluorescence microscopy examine how induces movement out living cells...
Whether mitotic structures like the centrosome can self-organize from regulated mobility of their dynamic protein components remains unclear. Here, we combine fluorescence spectroscopy and chemical genetics to study in living cells diffusion polo-like kinase 1 (PLK1), an enzyme critical for maturation at onset mitosis. The cytoplasmic a functional EGFP-PLK1 fusion correlates inversely with known changes its enzymatic activity during cell cycle. Specific inhibition using enhances mobility, as...
The function of the NaPiIIa renal sodium-phosphate transporter is regulated through a complex network interacting proteins. Several PDZ domain-containing proteins interact with its COOH terminus while small membrane protein MAP17 interacts NH(2) end. To elucidate MAP17, we identified using both bacterial and mammalian two-hybrid systems. proteins, including four NHERF as well NHE3, were found to bind MAP17. interactions further analyzed in opossum kidney (OK) cells. Expression alone had no...
In dietary potassium deficiency there is a decrease in the transport activity of type IIa sodium/phosphate cotransporter protein (NaPi) despite an increase its apical membrane abundance. This novel posttranslational regulation NaPi mediated by increased glycosphingolipid content potassium-deficient membrane. However, mechanisms which these lipids modulate have not been determined. We determined if increasingly partitioned cholesterol-, sphingomyelin-, and glycosphingolipid-enriched...
Flotillin 1 and flotillin 2 associate in the plasma membrane to form microdomains that have roles cell signaling, regulation of cell-cell contacts, membrane-cytoskeletal interactions, endocytosis. They are thought be involved trafficking hence processing Amyloid Precursor Protein, APP. In this study we set out obtain vivo confirmation a link between flotillins cleavage APP release amyloidogenic Aβ peptide, generate tools would allow us ask whether functionally redundant. We used mouse model...
The surface behaviour of swimming amoebae was followed in cells bearing a cAR1-paGFP (cyclic AMP receptor fused to photoactivatable-GFP) construct. Sensitized were placed buoyant medium where they could swim toward chemoattractant cAMP source. paGFP, activated at the cell’s front, remained fairly stationary frame as cell advanced; label not swept rearwards. Similar experiments with chemotaxing attached substratum gave same result. Furthermore, if region around lateral projection near...
We previously showed an inverse correlation between membrane cholesterol content and Na-P(i) cotransport activity during the aging process adaptation to alterations in dietary P(i) rat (Levi M, Jameson DM, van der Meer BW. Am J Physiol Renal Fluid Electrolyte 256: F85-F94, 1989). The purpose of present study was determine whether per se modulate apical protein expression opossum kidney (OK) cells. Acute depletion achieved with beta-methyl cyclodextrin (beta-MCD) resulted a significant...
Reconstruction of neuroanatomy is a fundamental problem in neuroscience. Stochastic expression colors individual cells promising tool, although its use the nervous system has been limited due to various sources variability expression. Moreover, intermingled anatomy neuronal trees challenging for existing segmentation algorithms. Here, we propose method automate neurons such (potentially pseudo-colored) images. The uses spatio-color relations between voxels, generates supervoxels reduce size...