Having reached the milestone of sequencing entire genomes, fundamental questions in understanding human biology are now: How are genomes organized in living cells and what are the mechanisms that determine what gene expression programs are active. Our cell biological studies of genomes and the cell nucleus are aimed at uncovering fundamental concepts of genome organization and nuclear function in vivo and they are providing opportunities for applying these principles to human disease diagnosis, therapeutics and bioengineering. To understand the nuclear environment in which genomes are expressed, we are probing the biophysical properties of proteins and chromatin using in vivo imaging. To this end, we generate functional, fluorescently labeled molecules, which can be introduced into cells and visualized in the nucleus of living cells by time-lapse microscopy. Using these methods we have succeeded in analyzing gene expression processes in living cells to study the structure-function relationship of the mammalian cell nucleus. Recently we have initiated studies to measure biophysical properties of proteins in vivo by using photobleaching techniques in conjunction with kinetic modeling and computer simulation approaches. These methods provide powerful tools to analyze for the first time at the molecular level the action of proteins in living cells and in real time. The second major issue in understanding how genomes function in cells is to determining how genomes are organized. To this end we have initiated studies to map the spatial organization of chromosomes within the nucleus and we are testing whether positioning of chromosomes affects gene expression and regulation. These studies must be considered first steps towards rigorous interphase cytogenetic methods. Finally, we are using our cell biological approaches to investigate the cellular organization of alternative splicing by investigating the differential association of pre-mRNA splicing factors with alternatively spliced transcripts. We have also initiated a study to apply our knowledge of alternative splice site selection to correct aberrant splicing in human disease genes with the hope to restore normal splicing in a 'RNA-therapy' approach.

Agency
National Institute of Health (NIH)
Institute
Division of Basic Sciences - NCI (NCI)
Type
Intramural Research (Z01)
Project #
1Z01BC010309-06
Application #
7051643
Study Section
(LRBG)
Project Start
Project End
Budget Start
Budget End
Support Year
6
Fiscal Year
2004
Total Cost
Indirect Cost
Name
Basic Sciences
Department
Type
DUNS #
City
State
Country
United States
Zip Code
Mathas, Stephan; Kreher, Stephan; Meaburn, Karen J et al. (2009) Gene deregulation and spatial genome reorganization near breakpoints prior to formation of translocations in anaplastic large cell lymphoma. Proc Natl Acad Sci U S A 106:5831-6
Misteli, Tom (2009) Self-organization in the genome. Proc Natl Acad Sci U S A 106:6885-6
Mejat, Alexandre; Decostre, Valerie; Li, Juan et al. (2009) Lamin A/C-mediated neuromuscular junction defects in Emery-Dreifuss muscular dystrophy. J Cell Biol 184:31-44
Pegoraro, Gianluca; Misteli, Tom (2009) The central role of chromatin maintenance in aging. Aging (Albany NY) 1:1017-22
Hager, Gordon L; McNally, James G; Misteli, Tom (2009) Transcription dynamics. Mol Cell 35:741-53
Soutoglou, Evi; Dorn, Jonas F; Sengupta, Kundan et al. (2007) Positional stability of single double-strand breaks in mammalian cells. Nat Cell Biol 9:675-82
Trotman, Lloyd C; Wang, Xinjiang; Alimonti, Andrea et al. (2007) Ubiquitination regulates PTEN nuclear import and tumor suppression. Cell 128:141-56
Soutoglou, Evi; Misteli, Tom (2007) Mobility and immobility of chromatin in transcription and genome stability. Curr Opin Genet Dev 17:435-42
Meaburn, Karen J; Misteli, Tom; Soutoglou, Evi (2007) Spatial genome organization in the formation of chromosomal translocations. Semin Cancer Biol 17:80-90
Kruhlak, Michael; Crouch, Elizabeth E; Orlov, Marika et al. (2007) The ATM repair pathway inhibits RNA polymerase I transcription in response to chromosome breaks. Nature 447:730-4

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