H2A.Z contributes to the unique 3D structure of the centromere.
نویسندگان
چکیده
Mammalian centromere function depends upon a specialized chromatin organization where distinct domains of CENP-A and dimethyl K4 histone H3, forming centric chromatin, are uniquely positioned on or near the surface of the chromosome. These distinct domains are embedded in pericentric heterochromatin (characterized by H3 methylated at K9). The mechanisms that underpin this complex spatial organization are unknown. Here, we identify the essential histone variant H2A.Z as a new structural component of the centromere. Along linear chromatin fibers H2A.Z is distributed nonuniformly throughout heterochromatin, and centric chromatin where regions of nucleosomes containing H2A.Z and dimethylated K4 H3 are interspersed between subdomains of CENP-A. At metaphase, using the inactive X chromosome centromere as a model, complex folding of this fiber produces spatially positioned domains where H2A.Z/dimethylated K4 H3 chromatin juxtaposes one side of CENP-A chromatin, whereas a region of H2A/trimethyl K9 H3 borders the other side. A second region of H2A.Z is found, with trimethyl K9 H3 at the inner centromere. We therefore propose that H2A.Z plays an integral role in organizing centromere structure.
منابع مشابه
Histone variant H2A.Z regulates centromere silencing and chromosome segregation in fission yeast.
The incorporation of histone variant H2A.Z into nucleosomes plays essential roles in regulating chromatin structure and gene expression. A multisubunit complex containing chromatin remodeling protein Swr1 is responsible for the deposition of H2A.Z in budding yeast and mammals. Here, we show that the JmjC domain protein Msc1 is a novel component of the fission yeast Swr1 complex and is required ...
متن کاملThe histone variant composition of centromeres is controlled by the pericentric heterochromatin state during the cell cycle.
Correct chromosome segregation requires a unique chromatin environment at centromeres and in their vicinity. Here, we address how the deposition of canonical H2A and H2A.Z histone variants is controlled at pericentric heterochromatin (PHC). Whereas in euchromatin newly synthesized H2A and H2A.Z are deposited throughout the cell cycle, we reveal two discrete waves of deposition at PHC - during m...
متن کاملP-217: Expression Analysis of The Histone Variant H2A.Z in Endometrium Tissue during The Menstrual Cycle
Background: The human endometrium undergoes cyclical changes including proliferation, differentiation, tissue breakdown and shedding (menstruation) throughout a woman’s reproductive life. The postovulatory rise in ovarian progestrone induces profound remodeling in chromatin structure of cells, and consequently differentiation of estradiol-primed endometrium. This change is crucial for embryo im...
متن کاملMsc1 acts through histone H2A.Z to promote chromosome stability in Schizosaccharomyces pombe.
As a central component of the DNA damage checkpoint pathway, the conserved protein kinase Chk1 mediates cell cycle progression when DNA damage is generated. Msc1 was identified as a multicopy suppressor capable of facilitating survival in response to DNA damage of cells mutant for chk1. We demonstrate that loss of msc1 function results in an increased rate of chromosome loss and that an msc1 nu...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
- Proceedings of the National Academy of Sciences of the United States of America
دوره 104 2 شماره
صفحات -
تاریخ انتشار 2007