@article{EisenhuthVellmerRauhetal.2021,
  author    = {Eisenhuth, Nicole and Vellmer, Tim and Rauh, Elisa T. and Butter, Falk and Janzen, Christian J.},
  title     = {A DOT1B/Ribonuclease H2 Protein Complex Is Involved in R-Loop Processing, Genomic Integrity, and Antigenic Variation in Trypanosoma brucei},
  series = {mbio},
  volume    = {12},
  journal   = {mbio},
  number    = {6},
  doi       = {10.1128/mBio.01352-21},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-260698},
  pages     = {e01352-21},
  year      = {2021},
  abstract  = {The parasite Trypanosoma brucei periodically changes the expression of protective variant surface glycoproteins (VSGs) to evade its host's immune sys-tem in a process known as antigenic variation. One route to change VSG expres-sion is the transcriptional activation of a previously silent VSG expression site (ES), a subtelomeric region containing the VSG genes. Homologous recombination of a different VSG from a large reservoir into the active ES represents another route. The conserved histone methyltransferase DOT1B is involved in transcriptional silencing of inactive ES and influences ES switching kinetics. The molecular machin-ery that enables DOT1B to execute these regulatory functions remains elusive, however. To better understand DOT1B-mediated regulatory processes, we purified DOT1B-associated proteins using complementary biochemical approaches. We iden-tified several novel DOT1B interactors. One of these was the RNase H2 complex, previously shown to resolve RNA-DNA hybrids, maintain genome integrity, and play a role in antigenic variation. Our study revealed that DOT1B depletion results in an increase in RNA-DNA hybrids, accumulation of DNA damage, and ES switch-ing events. Surprisingly, a similar pattern of VSG deregulation was observed in RNase H2 mutants. We propose that both proteins act together in resolving R-loops to ensure genome integrity and contribute to the tightly regulated process of anti-genic variation.},
  language  = {en}
}