Johannes Walter

Lab Head


Johannes Walter was born in Munich, Germany in 1967 and moved to the United States when he was one year old. He grew up in San Diego, California and went to college at UC Berkeley. In 1987, he participated in the undergraduate research program at Cold Spring Harbor Laboratory.  In 1989, he began graduate school at Yale University, where he studied transcriptional regulation in fruit flies, graduating with a Ph.D in Molecular Biophysics and Biochemistry. In 1995, he joined the laboratory of the late John Newport at UC San Diego.  There, he used frog egg extracts to develop the first soluble cell-free system that supports vertebrate chromosomal DNA replication. In 1999, he joined the faculty at Harvard Medical School (HMS) as an assistant professor in Biological Chemistry and Molecular Pharmacology. He was promoted to full professor in 2010 and joined the Howard Hughes Medical Institute in 2013.  He currently teaches DNA replication and repair in the graduate molecular biology course (BCMP200).

Dr. Walter’s lab has made the following contributions to our understanding of DNA replication and repair:

  • identified a replication-coupled proteolysis pathway that limits DNA replication to a single round per cell cycle
  • discovered how the replicative DNA helicase (CMG) interacts with DNA at the replication fork
  • elucidated two mechanisms of replication-coupled DNA interstrand cross-link (ICL) repair
  • showed that the Fanconi anemia pathway promotes incisions during ICL repair
  • discovered that DNA protein cross-links are repaired by a replication-coupled protease
  • elucidated the mechanism of replication termination in vertebrates
  • pioneered the use of frog egg extracts for single molecule studies of DNA replication and repair
Education and Positions
1985-1989 B.A. Biochemistry University of California Berkeley
1989-1995 Ph.D. Molecular Biophysics and Biochemistry Yale University
(supervisor, Mark Biggin)
1995-1999 Postdoctoral fellow University of California, San Diego
(supervisor, John Newport)
1999-2005 Assistant Professor Biological Chemistry & Molecular Pharmacology,
Harvard Medical School
2005-2010 Associate Professor Biological Chemistry & Molecular Pharmacology,
Harvard Medical School
2010-Present Professor Biological Chemistry & Molecular Pharmacology,
Harvard Medical School
Awards and Honors
1987 Undergraduate Research Program, Cold Spring Harbor Laboratory
1995-1998 NIH Post-Doctoral Fellowship
1998-2003 Burroughs Wellcome Career Award in the Biomedical Sciences
2000 William F. Milton Award
2000-2001 Giovanni-Armenise Foundation Award
2001-2002 Smith Family Award for Excellence in Biomedical Research
2005 Graduate teaching award
2006-2011 Leukemia and Lymphoma Society Scholar
2007 Graduate teaching award
2007 John and Virginia Kaneb Fellow
2008 AAAS fellow
2009 Graduate teaching award
2011 Graduate teaching award
2013-Present Howard Hughes Medical Institute Investigator
2018-2023 American Cancer Society Research Professor

For a complete list of Johannes Walter publications, click here