Projektbeschreibung
Analyse der Replikation posttranslationaler Histonmodifikationen
Nukleosomen sind DNA-Stränge, die um Histone (Proteine) gewickelt sind, und diese Art der Verpackung sorgt dafür, dass die DNA in den Zellkern passt. Dabei sind die sich wiederholenden Einheiten wie Perlen an einer Schnur aufgereiht, wie im Mikroskop sichtbar wird. Während der Transkription entwindet sich dieser DNA-Protein-Komplex (Chromatin), damit Transkriptionsfaktoren und andere DNA-bindende Proteine auf die DNA zugreifen können. Epigenetische Modifikationen an Histonproteinen (etwa Methylierung) können die Genexpression beeinflussen, was sich wiederum auf zelluläre Differenzierung, Gewebebildung und Immunsystem auswirkt. Obwohl klar ist, wie wichtig die ordnungsgemäße Replikation dieser posttranslationalen Modifikationen an der DNA vor der Zellteilung ist, sind die Mechanismen noch wenig erforscht. Um diesen wichtigen Prozess besser zu verstehen, analysiert das Projekt EpiRep nun die Assemblierung von Nukleosomen während der DNA-Replikation.
Ziel
Proper inheritance of the epigenetic information during cell division controls cell fate decisions, tissues homeostasis and development, ensuring disease avoidance. We have little understanding however of the mechanisms by which epigenetic information, specifically histone post-translational modifications in nucleosomes, are replicated in parallel to the DNA prior to cell division. This process strictly depends on proper nucleosome formation on the newly synthesized DNA strands. Here, I will study the molecular mechanism of nucleosome assembly during DNA replication. Nucleosome dynamics during DNA replication is controlled by an interconnected network of histone chaperones that converges on the key Chromatin Assembly Factor 1 (CAF-1). I recently elucidated the molecular mechanism of CAF-1-mediated nucleosome assembly, in absence of any other replication components. I developed a quantitative (NAQ) assay that allows, for the first time, the quantification of nucleosome assembly activity in vitro. In cells, CAF-1 is recruited to replication forks by the DNA polymerase processivity factor PCNA. Here, I will capitalize and expand on the assays above to integrate structural data, quantitative biochemical and biophysical measurements, and functional analyses, to elucidate how CAF-1 crosstalks to PCNA, DNA polymerases and other components of the DNA replication machinery in S phase. Specifically, the proposed research will 1) uncover how CAF-1 recruitment by PCNA affects its function in nucleosome assembly, and 2) examine how CAF-1 activity is regulated during ongoing DNA replication. This work will reveal the mechanism of nucleosome assembly during DNA replication and its interplay with S phase signaling. A mechanistic understanding of this pathway will uncover the fundamental principles that control genome and epigenome stability, thus cell fate decisions and disease avoidance.
Wissenschaftliches Gebiet
Schlüsselbegriffe
Programm/Programme
Thema/Themen
Finanzierungsplan
ERC-STG - Starting GrantGastgebende Einrichtung
1011 JV AMSTERDAM
Niederlande