PT - JOURNAL ARTICLE AU - Li Ding AU - Lukas Theo Schmitt AU - Melanie Brux AU - Duran Sürün AU - Martina Augsburg AU - Felix Lansing AU - Jovan Mircetic AU - Mirko Theis AU - Frank Buchholz TI - DNA methylation–independent long-term epigenetic silencing with dCRISPR/Cas9 fusion proteins AID - 10.26508/lsa.202101321 DP - 2022 Jun 01 TA - Life Science Alliance PG - e202101321 VI - 5 IP - 6 4099 - https://www.life-science-alliance.org/content/5/6/e202101321.short 4100 - https://www.life-science-alliance.org/content/5/6/e202101321.full SO - Life Sci. Alliance2022 Jun 01; 5 AB - The programmable CRISPR/Cas9 DNA nuclease is a versatile genome editing tool, but it requires the host cell DNA repair machinery to alter genomic sequences. This fact leads to unpredictable changes of the genome at the cut sites. Genome editing tools that can alter the genome without causing DNA double-strand breaks are therefore in high demand. Here, we show that expression of promoter-associated short guide (sg)RNAs together with dead Cas9 (dCas9) fused to a Krüppel-associated box domains (KRABd) in combination with the transcription repression domain of methyl CpG–binding protein 2 (MeCP2) can lead to persistent gene silencing in mouse embryonic stem cells and in human embryonic kidney (HEK) 293 cells. Surprisingly, this effect is achievable and even enhanced in DNA (cytosine-5)-methyltransferase 3A and 3B (Dnmt3A−/−, Dnmt3b−/−) depleted cells. Our results suggest that dCas9-KRABd-MeCP2 fusions are useful for long-term epigenetic gene silencing with utility in cell biology and potentially in therapeutical settings.