Rahul Kohli obtained a B.S. in biochemistry from the University of Michigan and an M.D. from Harvard Medical School, where he also conducted Ph.D. studies under Christopher T. Walsh. He subsequently completed clinical training in internal medicine and infectious diseases and conducted postdoctoral studies with James Stivers at Johns Hopkins University. In 2010 Kohli joined the faculty of the University of Pennsylvania. His research has garnered support from the Doris Duke Foundation and the Burroughs Wellcome Fund, as well as a National Institutes of Health Director’s New Innovator Award. Kohli’s studies on the role of cytosine-modifying enzymes in adaptive immunity and pluripotency have been supported by awards from the NIH and the Rita Allen Foundation.
Since the decoding of the human genome, it is increasingly evident that nature’s diversity is not fully explained by the simple, static sequence of DNA. The genome constantly undergoes transformation through chemical modification of DNA bases, which adds an additional and essential layer of complexity. While these chemical transformations can be purposeful, yielding variety in cell lineages or in antibody molecules, they can also pose significant risks. Most notably, aberrant action of these DNA-modifying pathways can promote oncogenesis. Many of these significant modifications are focused on cytosine residues throughout the genome, with alterations that include methylation, deamination or oxidation. Understanding the enzymes and pathways that catalyze the modification of cytosine can provide insight into how purposeful alterations are promoted over oncogenic transformations. Kohli’s research has helped to reveal the previously enigmatic mechanism by which cytosine bases can be demethylated—a transformation that is critical to the generation of pluripotent stem cells, but one that can also promote myeloid cancers when perturbed. His group’s work has revealed a nonessential role for AID/APOBEC family enzymes in demethylation and helped to establish an oxidation-repair mediated pathway for demethylation initiated by TET family enzymes.