Johannes Walter

  • Latest publications

    Dewar, J.D., Budzowska, M., Walter, J.C. (2015). The mechanism of DNA replication termination in vertebrates. Nature 525, 345-350.

    Budzowska, M., Graham, T.G., Sobeck, A., Waga, S., and Walter, J.C. (2015). Regulation of the Rev1-pol zeta complex during bypass of a DNA interstrand cross-link. EMBO J.

    Zhang, J., Dewar, J.M., Budzowska, M., Motnenko, A., Cohn, M.A., and Walter, J.C. (2015). DNA interstrand cross-link repair requires replication fork convergence. NSMB 11, 242-247.

    Duxin, J.P., Dewar, J.M., Yardimci, H., and Walter, J.C. (2014). Replication-coupled repair of a DNA-protein crosslink. Cell 159, 346-357.

    Long, D.T., Joukov, V., Budzowska, M., and Walter, J.C. (2014). BRCA1 promotes unloading of the CMG helicase from a stalled DNA replication fork. Molecular Cell 56, 174-185.

  • Prizes and Awards

    Graduate teaching award, 2011; 2009; 2007; 2005

    AAAS fellow, 2008

    John and Virginia Kaneb Fellow, 2007

    Leukemia and Lymphoma Society Scholar, 2006

    Smith Family Award for Excellence in Biomedical Research, 2001

    Armenise-Harvard Junior Faculty Grant, 2000

    Department of Integrative Biology & Physiology: “Initiation of Eukarotic DNA Replication”, 2000

    William F. Milton Award, 2000

    Burroughs Wellcome Career Award in the Biomedical Sciences, 1998

Who he is

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 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). In 2013, Dr. Walter joined the Howard Hughes Medical Institute.

What he does

Dr. Walter studies how vertebrate cells faithfully duplicate their  genomes in S phase using egg extracts from the African clawed toad, Xenopus laevis.  These extracts are remarkable in that they recapitulate key processes underlying genome propagation, including DNA replication, the ATR and ATM checkpoints, chromosome cohesion, ubiquitin-mediated proteolysis, many DNA repair pathways, and the segregation of chromosomes in mitosis.

The lab seeks to understand the molecular machines that carry out DNA replication and how these machines are regulated by ubiquitin-mediated proteolysis to limit genome duplication to exactly one round per cell cycle.  His lab studies DNA inter-strand cross-link repair and how this process goes awry in the human genetic disorder, Fanconi anemia.

News from the Lab

Most recently, the Walter lab has studied the repair of DNA protein cross-links (DPC). They found that like ICL repair, DPC repair is coupled to DNA replication and involves a protease that destroys the DPC on DNA, allowing replicative bypass. They also developed a new system to induce site-specific and synchronous replication termination. This approach revealed that converging DNA replication forks do not slow down and that the replicative DNA helicases pass each other and are unloaded from double-stranded DNA.