Nils G. Walter, Ph.D.

Professor, Chemistry
Professor, Biological Chemistry

2405 Chemistry
930 N. University Avenue
Ann Arbor, MI 48109-1055

 

(734) 615-2060

Areas of Interest

At the interface of Biology and Chemistry, a revolution has recently taken place that has uncovered a plethora of small non-coding RNAs (ncRNAs) in our bodies, which outnumber protein-coding genes by several-fold, dominate the expression patterns of all genes in all cells, and have inspired entirely new therapeutic disease intervention approaches. Our group's goal is to understand the mechanistic structure-function relationships in these ncRNAs using single molecule tools and then utilize them for biomedical, bioanalytical and nanotechnological applications. The ncRNAs we study range from small RNA enzymes, such as the hammerhead, hairpin and hepatitis delta virus ribozymes with potential use in human gene therapy and relevance to human disease, to large RNA-protein complexes, such as RNA interference machinery involved in gene regulation and virus suppression. In particular, we employ fluorescence techniques to study in real-time the kinetic mechanisms of these ncRNAs, in bulk solution, in live cells, and at the single-molecule level. Applications include the identification and optimization of ncRNAs for gene therapy and as novel biosensors and biomarkers, as well as the characterization of antiviral and antibiotic drugs that target pathogenic RNA function.

Our research by its very nature is highly interdisciplinary, engaging students with a diverse background and providing a broad education. The molecules we study are extremely dynamic over time scales of microseconds to hours. To understand these dynamics we combine state-of-the-art biochemical, molecular biological, and biophysical approaches. An outline of several exciting current projects is given below.

1. Dissecting pre-mRNA splicing by fluorophore labeling individual RNA or protein components and following their fluorescence fluctuations during splicing in cell extracts by single molecule fluorescence microscopy.

2. Using single molecule fluorescence techniques to observe in unprecedented detail fluctuations of single ncRNA molecules between functionally active and inactive conformations.

3. Utilizing single molecule fluorescence imaging to follow movement of the ribosome on a secondary structured mRNA, including riboswitch motifs that utilize an aptamer domain to recognize a specific ligand and effect downstream gene expression.

4. Developing a model system for understanding gene silencing by directly observing, using fluorescence techniques, the action of small interfering (si)RNAs and micro (mi)RNAs on pathogenic mRNAs in cell extracts and live cells.

5. Utilizing super-resolution fluorescence imaging techniques in nanotechnology to follow and optimize autonomously moving engineered "molecular spiders" and the functionality of other RNA and DNA nanodevices.

Research Areas

Analytical Chemistry • Bioanalytical Chemistry • Bioinorganic Chemistry • Biophysical Chemistry • Chemical Biology • Energy Science • Nano Chemistry • Optics and Imaging • Organic Chemistry • Physical Chemistry • RNA Biochemistry • Sensor Science • Surface Chemistry • Sustainable Chemistry • Ultrafast Dynamics

Other Research Interests

  • Single Molecule Fluorescence Spectroscopy and Microscopy
  • Folding and Function of Non-Coding RNA
  • Live-Cell Imaging
  • Biophysical Chemistry of Nucleic Acids

Honors & Awards

Visiting Sabbatical Scholar, Chan-Zuckerberg Biohub, San Francisco (hosted by Stephen Quake), 2018
Prasanta Datta Memorial Travel Award, Department of Biological Chemistry, University of Michigan, 2018
Francis S. Collins Collegiate Professor, University of Michigan, 2017
Mid-Career Award, RNA Society, 2017
Jean Dreyfus Boissevain Lecturer, Trinity University, San Antonio, TX, 2015
Harold R. Johnson Diversity Service Award, University of Michigan, 2015
Faculty Recognition Award, University of Michigan, 2013
Imes and Moore Faculty Award, University of Michigan, 2013
Alexander von Humboldt Foundation Visiting Scholar, Johann Wolfgang Goethe University Frankfurt (Harald Schwalbe group), 2012
Elected Fellow, American Association for the Advancement of Science, 2011
Buchanan Lecturer, Bowling Green State University, 2011
ADVANCE Program for Executive Leadership, University of Michigan, 2011
MSFB Study Section Member, National Institutes of Health, 2009–2013
Visiting Sabbatical Scholar, Harvard University (Sunney Xie group), 2006
JILA Distinguished Visitor Fellowship (David Nesbitt group), 2006
Alumnus of the Year Award, Sherbrooke RiboClub, 2006
Camille Dreyfus Teacher-Scholar Award, 2004
Dow Corning Assistant Professorship, University of Michigan, 2002
Otto-Hahn Award for Outstanding Researchers of the Max-Planck Society, 1995
Feodor-Lynen Postdoctoral Research Fellowship, Alexander von Humboldt Foundation, 1995–1998
Kekulé Predoctoral Scholarship, Fund of the German Chemical Industry Association, 1992–1994

Published Articles or Reviews

Recent Publications

Dynamic competition between a ligand and transcription factor NusA governs riboswitch-mediated transcription regulation.
Chauvier A, Ajmera P, Yadav R, Walter NG.
Proc Natl Acad Sci U S A. 2021; 118: e2109026118.

Rapid kinetic fingerprinting of single nucleic acid molecules by a FRET-based dynamic nanosensor.
Khanna K, Mandal S, Blanchard AT, Tewari M, Johnson-Buck A, Walter NG.
Biosens Bioelectron. 2021; 190: 113433.

A translational riboswitch coordinates nascent transcription-translation coupling.
Chatterjee S, Chauvier A, Dandpat SS, Artsimovitch I, Walter NG.
Proc Natl Acad Sci U S A. 2021; 118: e2023426118.

Sisyphus observed: Unraveling the high ATP usage of an RNA chaperone.
Duran EC, Walter NG.
J Biol Chem. 2021; 296: 100265.

Regulating DNA Self-Assembly Dynamics with Controlled Nucleation.
Jiang S, Pal N, Hong F, Fahmi NE, Hu H, Vrbanac M, Yan H, Walter NG, Liu Y.
ACS Nano. 2021; 15: 5384–96.

Single bacterial resolvases first exploit, then constrain intrinsic dynamics of the Holliday junction to direct recombination.
Ray S, Pal N, Walter NG.
Nucleic Acids Res. 2021; 49: 2803–15.

Transcriptional Riboswitches Integrate Timescales for Bacterial Gene Expression Control.
Scull CE, Dandpat SS, Romero RA, Walter NG.
Front Mol Biosci. 2021; 7: 607158.

Hyperosmotic phase separation: Condensates beyond inclusions, granules and organelles.
Jalihal AP, Schmidt A, Gao G, Little S, Pitchiaya S, Walter NG.
J Biol Chem. 2021; 296: 100044.

For a list of publications from PubMed, click HERE

Web Sites