The Library
Self-assembly and DNA binding of the blocking factor in X chromosome inactivation
Tools
Nicodemi, Mario and Prisco, Antonella (2007) Self-assembly and DNA binding of the blocking factor in X chromosome inactivation. PLoS Computational Biology, Vol.3 (No.11). pp. 2135-2142. doi:10.1371/journal.pcbi.0030210 ISSN 1553-734X.
|
PDF
WRAP_Nicodemi_Self-Assembly_plos.pdf - Requires a PDF viewer. Download (524Kb) |
Official URL: http://dx.doi.org/10.1371/journal.pcbi.0030210
Abstract
X chromosome inactivation (XCI) is the phenomenon occurring in female mammals whereby dosage compensation of
X-linked genes is obtained by transcriptional silencing of one of their two X chromosomes, randomly chosen during
early embryo development. The earliest steps of random X-inactivation, involving counting of the X chromosomes and
choice of the active and inactive X, are still not understood. To explain "counting and choice," the longstanding
hypothesis is that a molecular complex, a "blocking factor" (BF), exists. The BF is present in a single copy and can
randomly bind to just one X per cell which is protected from inactivation, as the second X is inactivated by default. In
such a picture, the missing crucial step is to explain how the molecular complex is self-assembled, why only one is
formed, and how it binds only one X. We answer these questions within the framework of a schematic Statistical
Physics model, investigated by Monte Carlo computer simulations. We show that a single complex is assembled as a
result of a thermodynamic process relying on a phase transition occurring in the system which spontaneously breaks
the symmetry between the X’s. We discuss, then, the BF interaction with X chromosomes. The thermodynamics of the
mechanism that directs the two chromosomes to opposite fates could be, thus, clarified. The insights on the selfassembling
and X binding properties of the BF are used to derive a quantitative scenario of biological implications
describing current experimental evidences on "counting and choice."
Item Type: | Journal Article | ||||
---|---|---|---|---|---|
Subjects: | Q Science > QH Natural history > QH426 Genetics | ||||
Divisions: | Faculty of Science, Engineering and Medicine > Science > Physics | ||||
Library of Congress Subject Headings (LCSH): | X chromosome, Gene silencing -- Computer simulation | ||||
Journal or Publication Title: | PLoS Computational Biology | ||||
Publisher: | Public Library of Science | ||||
ISSN: | 1553-734X | ||||
Official Date: | 9 November 2007 | ||||
Dates: |
|
||||
Volume: | Vol.3 | ||||
Number: | No.11 | ||||
Number of Pages: | 8 | ||||
Page Range: | pp. 2135-2142 | ||||
DOI: | 10.1371/journal.pcbi.0030210 | ||||
Status: | Peer Reviewed | ||||
Publication Status: | Published | ||||
Access rights to Published version: | Open Access (Creative Commons) | ||||
Funder: | Italy. Ministero dell'istruzione, dell'università e della ricerca (MIUR), Fondo per gli Investimenti della Ricerca di Base (FIRB) | ||||
Grant number: | RBNE01S29H (MIUR-FIRB), Network MRTN-CT-2003–504712 |
Data sourced from Thomson Reuters' Web of Knowledge
Request changes or add full text files to a record
Repository staff actions (login required)
View Item |
Downloads
Downloads per month over past year