Solid Phase Synthesis of a Functionalized Bis-Peptide Using …
Published 5/15/2012
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In JoVE (1)
Other Publications (1)
Articles by Urszula Polak in JoVE
Selecting and Isolating Colonies of Human Induced Pluripotent Stem Cells Reprogrammed from Adult Fibroblasts
1Department of Molecular Carcinogenesis and Center for Cancer Epigenetics, University of Texas M.D. Anderson Cancer Center, 2Department of Cell Biology, Poznan University of Medical Sciences, 3Department of Molecular Biology, The Scripps Research Institute
We present a protocol for efficient reprogramming of human somatic cells into human induced pluripotent stem cells (hiPSC) using retroviral vectors encoding Oct3/4, Sox2, Klf4 and c-myc (OSKM) and identification of correctly reprogrammed hiPSC by live staining with Tra-1-81 antibody.
Other articles by Urszula Polak on PubMed
New Insights into Repeat Instability: Role of RNA•DNA Hybrids
Expansion of tandem repeat sequences is responsible for more than 20 human diseases. Several cis elements and trans factors involved in repeat instability (expansion and contraction) have been identified. However no comprehensive model explaining large intergenerational or somatic changes of the length of the repeating sequences exists. Several lines of evidence, accumulated from different model studies, indicate that transcription through repeat sequences is an important factor promoting their instability. The persistent interaction between transcription template DNA and nascent RNA (RNA•DNA hybrids, R loops) was shown to stimulate genomic instability. Recently, we demonstrated that cotranscriptional RNA•DNA hybrids are preferentially formed at GC-rich trinucleotide and tetranucleotide repeat sequences in vitro as well as in human genomic DNA. Additionally, we showed that cotranscriptional formation of RNA•DNA hybrids at CTG•CAG and GAA•TTC repeats stimulate instability of these sequences in both E. coli and human cells. Our results suggest that persistent RNA•DNA hybrids may also be responsible for other downstream effects of expanded trinucleotide repeats, including gene silencing. Considering the extent of transcription through the human genome as well as the abundance of GC-rich and/or non-canonical DNA structure forming tandem repeats, RNA•DNA hybrids may represent a common mutagenic conformation. Hence, R loops are potentially attractive therapeutic target in diseases associated with genomic instability.