Role of chromatin bound nuclear pore complex components in gene expression
04 / 2011 - onbekend
Nuclear pore complexes (NPCs) mediate all traffic to and from the eukaryotic nucleus. Their direct role in genome function is less well understood. Recently, we found that in Drosophila components of the NPC interact with the genome in two different places within the nucleus: at the NPC and inside the nucleoplasm. Inside the nucleoplasm, nucleoporins interact with developmentally important genes and promote their expression. How nucleoporins achieve this is unclear. At the NPCs nucleoporins interact with different sets of developmental genes. Contrary to expectations these genes are not particularly active, and the function of the NPC interaction remains unknown. We propose to elucidate the mechanism of both types of interactions using recently aquired nucleoporin-chromatin interaction maps, and investigate the function of NPC-tethered chromatin. To understand NPC tethering, we will assay both NPC and DNA requirements. Interfering with these requirements will show the effects of NPC tethering on proximal gene expression events, nucleocytoplasmic transport and global chromatin structure. To understand the mechanism of nucleoporin-dependent gene activation we will identify pathway components by purifying nucleoplasmic nucleoporin complexes followed by mass spectrometry. Also we will screen known nucleoporin binding factors including mRNA export factors for similarities in genomic interactions. Candidate factors will be tested for their function in nucleoporin pathways. With this we aim to elucidate (1) the function of the specific genomic interactions at the NPC and (2) how nucleoplasmic nucleoporins stimulate gene expression.