All Publications


  • Tunable and reversible drug control of protein production via a self-excising degron. Nature chemical biology Chung, H. K., Jacobs, C. L., Huo, Y., Yang, J., Krumm, S. A., Plemper, R. K., Tsien, R. Y., Lin, M. Z. 2015; 11 (9): 713-720

    Abstract

    An effective method for direct chemical control over the production of specific proteins would be widely useful. We describe small molecule-assisted shutoff (SMASh), a technique in which proteins are fused to a degron that removes itself in the absence of drug, resulting in the production of an untagged protein. Clinically tested HCV protease inhibitors can then block degron removal, inducing rapid degradation of subsequently synthesized copies of the protein. SMASh allows reversible and dose-dependent shutoff of various proteins in multiple mammalian cell types and in yeast. We also used SMASh to confer drug responsiveness onto an RNA virus for which no licensed inhibitors exist. As SMASh does not require the permanent fusion of a large domain, it should be useful when control over protein production with minimal structural modification is desired. Furthermore, as SMASh involves only a single genetic modification and does not rely on modulating protein-protein interactions, it should be easy to generalize to multiple biological contexts.

    View details for DOI 10.1038/nchembio.1869

    View details for PubMedID 26214256

    View details for PubMedCentralID PMC4543534

  • A Single-Chain Photoswitchable CRISPR-Cas9 Architecture for Light-Inducible Gene Editing and Transcription A Single-Chain Photoswitchable CRISPR-Cas9 Architecture for Light-Inducible Gene Editing and Transcription Zhou, X. X., Zou, X., Chung, H. K., Gao, Y., Liu, Y., QI, L. S., Lin, M. Z. 2017
  • Replication-Competent Influenza Virus and Respiratory Syncytial Virus Luciferase Reporter Strains Engineered for Co-Infections Identify Antiviral Compounds in Combination Screens. Biochemistry Yan, D., Weisshaar, M., Lamb, K., Chung, H. K., Lin, M. Z., Plemper, R. K. 2015; 54 (36): 5589-5604

    Abstract

    Myxoviruses such as influenza A virus (IAV) and respiratory syncytial virus (RSV) are major human pathogens, mandating the development of novel therapeutics. To establish a high-throughput screening protocol for the simultaneous identification of pathogen- and host-targeted hit candidates against either pathogen or both, we have attempted co-infection of cells with IAV and RSV. However, viral replication kinetics were incompatible, RSV signal window was low, and an IAV-driven minireplicon reporter assay used in initial screens narrowed the host cell range and restricted the assay to single-cycle infections. To overcome these limitations, we developed an RSV strain carrying firefly luciferase fused to an innovative universal small-molecule assisted shut-off domain, which boosted assay signal window, and a hyperactive fusion protein that synchronized IAV and RSV reporter expression kinetics and suppressed the identification of RSV entry inhibitors sensitive to a recently reported RSV pan-resistance mechanism. Combined with a replication-competent recombinant IAV strain harboring nanoluciferase, the assay performed well on a human respiratory cell line and supports multicycle infections. Miniaturized to 384-well format, the protocol was validated through screening of a set of the National Institutes of Health Clinical Collection (NCC) in quadruplicate. These test screens demonstrated favorable assay parameters and reproducibility. Application to a LOPAC library of bioactive compounds in a proof-of-concept campaign detected licensed antimyxovirus therapeutics, ribavirin and the neuraminidase inhibitor zanamivir, and identified two unexpected RSV-specific hit candidates, Fenretinide and the opioid receptor antagonist BNTX-7. Hits were evaluated in direct and orthogonal dose-response counterscreens using a standard recRSV reporter strain expressing Renilla luciferase.

    View details for DOI 10.1021/acs.biochem.5b00623

    View details for PubMedID 26307636

    View details for PubMedCentralID PMC4719150

  • Optical Control of Protein Activity by Fluorescent Protein Domains SCIENCE Zhou, X. X., Chung, H. K., Lam, A. J., Lin, M. Z. 2012; 338 (6108): 810-814

    Abstract

    Fluorescent proteins (FPs) are widely used as optical sensors, whereas other light-absorbing domains have been used for optical control of protein localization or activity. Here, we describe light-dependent dissociation and association in a mutant of the photochromic FP Dronpa, and we used it to control protein activities with light. We created a fluorescent light-inducible protein design in which Dronpa domains are fused to both termini of an enzyme domain. In the dark, the Dronpa domains associate and cage the protein, but light induces Dronpa dissociation and activates the protein. This method enabled optical control over guanine nucleotide exchange factor and protease domains without extensive screening. Our findings extend the applications of FPs from exclusively sensing functions to also encompass optogenetic control.

    View details for DOI 10.1126/science.1226854

    View details for Web of Science ID 000310839500048

    View details for PubMedID 23139335

    View details for PubMedCentralID PMC3702057