Characterization of SRA-DNA complexes involved in Chromatin structure regulation by novel single-molecule fluorescence imaging technique
* SPEAKERS
Name
Affiliation
E-mail
Yong-Woon Han
Kyoto University
* HOST(Applicant)
Name
Affiliation
E-mail
Junghyo Jo
APCTP
jojunghyo(at)apctp.org
* DATE / TIME
2013-05-24, 3pm
* ABSTRACT
Eukaryotic gene expression is regulated by chromatin structures and/or DNA modification such as CpG methylation. The basic unit of eukaryotic chromatin structure is a nucleosome consisting of approximately 150 bp DNA wrapped in 1.7 superhelical turns around a histone octamer. The histone octamer consists of two copies each of H2A, H2B, H3 and H4. Posttranslational histone modifications such as acetylation, methylation, phosphorylation and ubiquitylation regulate chromatin structure, resulting in activation or repression of gene expression. On the other hand, CpG methylation represses gene expression and is essential for silencing of parasitic DNA, genomic imprinting and embryogenesis. During DNA replication, methylated CpGs are converted into hemi-methylated CpGs and newly replicated CpGs should be methylated to inherit methylation pattern. DNA methyltransferase 1 (Dnmt1) is the enzyme to methylate hemi-methylated CpG regions. Uhrf1 is methylated CpG binding protein and interacts with Dnmt1, followed by recruitment of Dnmt1 to hemi-methylated CpG regions. SRA domain of Uhrf1 is responsible for hemi-methylated CpG binding activity. We characterize the DNA binding activity of SRA domain using novel Single-Molecule technique, and in this seminar, I will show our present data.
