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    Stephen C Miller PhD

    TitleAssociate Professor
    InstitutionUniversity of Massachusetts Medical School
    DepartmentBiochemistry and Molecular Pharmacology
    AddressUniversity of Massachusetts Medical School
    364 Plantation Street, LRB
    Worcester MA 01605
    Phone508-856-8865
      Other Positions
      InstitutionUMMS - Graduate School of Biomedical Sciences
      DepartmentBiochemistry and Molecular Pharmacology

      InstitutionUMMS - Graduate School of Biomedical Sciences
      DepartmentInterdisciplinary Graduate Program

      InstitutionUMMS - Graduate School of Biomedical Sciences
      DepartmentTranslational Science

      InstitutionUMMS - Programs, Centers and Institutes
      DepartmentChemical Biology

        Overview 
        Narrative

        Illuminating biological processes with chemistry

        Photo: Stephen Miller

        Our laboratory has two main objectives: 1) non-invasive optical imaging of the intracellular environment with fluorescence and bioluminescence, and 2) spatial and temporal control over protein function. To achieve these goals, we synthesize small molecules that absorb and/or emit light.

        • Optical probes of the intracellular environment

        Fluorescent molecules. Study of the intracellular environment using fluorescence is limited by the inherent absorbance of living tissues. Most optical probes in use today absorb and emit light in the visible wavelength region. Absorption of visible wavelength light by cellular components (e.g., flavins, porphyrins) generates excited state molecules that can give rise to background fluorescence and phototoxicity. In whole animals such as the mouse, absorption of light by the hemoglobin in blood is so great that visible wavelength fluorescence is not viable for imaging.

        Living tissue is most transparent to light beyond the visible range, in a spectral region known as the near-IR (650-900 nm). Although this is the ideal spectral window for any optical probe of living cells or organisms, most near-IR fluorophores are unsuitable for use in the intracellular environment because they either lack cell-permeability or give high-background labeling of cellular organelles and membranes. One of our major goals is the design and application of new near-IR fluorophores and probes that can freely enter living cells and facilitate studies of specific intracellular events.

        Bioluminescent molecules. Luciferase-catalyzed light emission can also be used to report on the intracellular environment, and can be used in live animals such as the mouse. Nonetheless, the properties of luciferase are inherently limited by the ability of the luciferin substrate to access the luciferase, and by its photophysical properties (e.g., emission wavelength). Work in our lab is directed toward the development and optimization of luciferases and luciferins for applications ranging from high-throughput screening to bioluminescence imaging in mice.

        • Photocontrol of protein function

        To exert spatial and temporal control over cellular processes, our lab is using the power of chemistry to synthesize molecules that can block the activation and interactions of specific proteins. Upon irradiation with light, these molecules either fall apart or rearrange to restore protein function. For example, the location and timing of GTPase activation is critical for proper cell function, but is still poorly understood. We will use this photoactivation approach to study these rapid processes in living cells using fluorescence microscopy.



        Rotation Projects

        Rotation Projects

        Work in our lab focuses on chemical approaches to the study of living cells. This multi-disciplinary approach brings together the areas of synthetic organic chemistry, molecular biology, biochemistry and cell biology.

        1) Delivery of fluorescent probes to intracellular targets: Fluorescent tagging of proteins with GFP has been widely used to study protein localization in living cells. However, the large size of GFP can often prove disruptive to protein function and/or localization. Moreover, the visible wavelength fluorescence of GFP contributes to background autofluorescence and phototoxicity, and GFP is not useful for imaging in animals such as mice. We are developing near-IR fluorophores that can be used to label intracellular proteins, as well as targeting strategies to specifically label macromolecules with exogenously-applied molecules.

        2) Near-IR fluorescent probes. Fluorescent sensors of enzymatic activity, metal ions, and small molecules allow the optical detection of biologically-important molecules. However, most of these sensors are based on visible-wavelength fluorophores that have limited utility in live cells, and are generally unusable in live organisms such as mice. We are designing and constructing near-IR sensors which are suitable for the non-invasive optical imaging of the physiological state of live cells and organisms.

        3) Improved bioluminescence imaging: Bioluminescence results from the chemical generation of light, and thus unlike fluorescence does not require irradiation. We have synthesized a variety of novel luciferin substrates designed to improve the ability to detect bioluminescence signals. We will utilize these luciferins to image gene expression, enzyme function, and other biological states both in vitro and in vivo.

        4) Spatio-temporal control of GTPases: GTPases act as molecular switches to control a wide variety of dynamic cellular processes. Key to their proper function is the location and timing of their activation (and inactivation). We employ chemical approaches to allow the rapid activation and inactivation of these proteins using light. With these tools in hand, we will study the essential roles of localization and timing in the proper transduction of biological signals.



        Bibliographic 
        selected publications
        List All   |   Timeline
        1. Adams ST, Miller SC. Beyond D-luciferin: expanding the scope of bioluminescence imaging in vivo. Curr Opin Chem Biol. 2014 Jul 28; 21C:112-120.
          View in: PubMed
        2. Mofford DM, Reddy GR, Miller SC. Latent luciferase activity in the fruit fly revealed by a synthetic luciferin. Proc Natl Acad Sci U S A. 2014 Mar 25; 111(12):4443-8.
          View in: PubMed
        3. Evans MS, Chaurette JP, Adams ST, Reddy GR, Paley MA, Aronin N, Prescher JA, Miller SC. A synthetic luciferin improves bioluminescence imaging in live mice. Nat Methods. 2014 Apr; 11(4):393-5.
          View in: PubMed
        4. Godinat A, Park HM, Miller SC, Cheng K, Hanahan D, Sanman LE, Bogyo M, Yu A, Nikitin GF, Stahl A, Dubikovskaya EA. A biocompatible in vivo ligation reaction and its application for noninvasive bioluminescent imaging of protease activity in living mice. ACS Chem Biol. 2013 May 17; 8(5):987-99.
          View in: PubMed
        5. Pauff SM, Miller SC. A trifluoroacetic acid-labile sulfonate protecting group and its use in the synthesis of a near-IR fluorophore. J Org Chem. 2013 Jan 18; 78(2):711-6.
          View in: PubMed
        6. Harwood KR, Mofford DM, Reddy GR, Miller SC. Identification of mutant firefly luciferases that efficiently utilize aminoluciferins. Chem Biol. 2011 Dec 23; 18(12):1649-57.
          View in: PubMed
        7. Pauff SM, Miller SC. Synthesis of near-IR fluorescent oxazine dyes with esterase-labile sulfonate esters. Org Lett. 2011 Dec 2; 13(23):6196-9.
          View in: PubMed
        8. Rusha L, Miller SC. Design and application of esterase-labile sulfonate protecting groups. Chem Commun (Camb). 2011 Feb 21; 47(7):2038-40.
          View in: PubMed
        9. Reddy GR, Thompson WC, Miller SC. Robust light emission from cyclic alkylaminoluciferin substrates for firefly luciferase. J Am Chem Soc. 2010 Oct 6; 132(39):13586-7.
          View in: PubMed
        10. Miller SC. Profiling sulfonate ester stability: identification of complementary protecting groups for sulfonates. J Org Chem. 2010 Jul 2; 75(13):4632-5.
          View in: PubMed
        11. Harwood KR, Miller SC. Leveraging a small-molecule modification to enable the photoactivation of rho GTPases. Chembiochem. 2009 Dec 14; 10(18):2855-7.
          View in: PubMed
        12. Bhunia AK, Miller SC. Labeling tetracysteine-tagged proteins with a SplAsH of color: a modular approach to bis-arsenical fluorophores. Chembiochem. 2007 Sep 24; 8(14):1642-5.
          View in: PubMed
        13. Miller SC, Mitchison TJ. Synthesis and phenotypic screening of a Guanine-mimetic library. Chembiochem. 2004 Jul 5; 5(7):1010-2.
          View in: PubMed
        14. Miller SC, Scanlan TS. J. Am. Chem. Soc. oNBS-SPPS: A New Method for Solid-Phase Peptide Synthesis. 1998; 120:2690-1.
        15. Miller SC, Scanlan TS. J. Am. Chem. Soc. Site-Selective N-Methylation of Peptides on Solid Support. 1997; 119:2301-2.
        16. Truckses DM, Somoza JR, Prehoda KE, Miller SC, Markley JL. Coupling between trans/cis proline isomerization and protein stability in staphylococcal nuclease. Protein Sci. 1996 Sep; 5(9):1907-16.
          View in: PubMed
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