tailieunhanh - Báo cáo Y học: Beyond the ABCs of CKC and SCC Do centromeres orchestrate sister chromatid cohesion or vice versa?

The centromere–kinetochore complex is a highly specialized chromatin domain that both mediates and monitors chromosome–spindle interactions responsible for accurate partitioning of sister chromatids to daughter cells. Centromeres are distinguished from adjacent chromatin by specific patterns of histone modification and the presence of a centromere-specific histone H3 variant (. CENP-A). Centromere-proximal regions usually correspond to sites of avid and persistent sister chromatid cohesion mediated by the conserved cohesin complex. In budding yeast, there is a substantial body of evidence indicating centromeres direct formation and/or stabilization of centromere-proximal cohesion. In other organisms, the dependency of cohesion on centromere function is not as clear | Eur. J. Biochem. 269 2300-2314 2002 FEBS 2002 doi MINIREVIEW Beyond the ABCs of CKC and SCC Do centromeres orchestrate sister chromatid cohesion or vice versa Pamela B. Meluh1 and Alexander V. Strunnikov2 1 Memorial Sloan-Kettering Cancer Center Laboratory of Mechanism and Regulation of Mitosis New York USA 2 Unit of Chromosome Structure and Function NIH NICHD Laboratory of Gene Regulation and Development Bethesda MD USA The centromere-kinetochore complex is a highly specialized chromatin domain that both mediates and monitors chromosome-spindle interactions responsible for accurate partitioning of sister chromatids to duiighler cells. Centromeres are distinguished from adjacent chromatin by specific patterns of histone modihcaiion and the presence of a centromere-specific histone H3 variant . CENP-A . Centromere-proximal regions usually correspond to sites of avid and persistent sister chromatid cohesion mediated by the conserved cohesin complex. In budding yeast there is a substantial body ofevidence indicating centromeres direct formation and or stabilization of centromere-proximal cohesion. In other organisms the dependency ofcohesion on centromere function is not as clear. Indeed it appears that pericentromeric heterochromatin recruits cohesion proteins independent ofcentromere function. Nonetheless aspects of centromere function are impaired in the absence of sister chromatid cohesion suggesting the two are interdependent. Here we review the nature of em chromhtin the dynamics and regulation ofsister chromatid cohesion and the relationship between the two. Keywords centromere kinetochore CENP-A histone methylation heterochromatin sister chromatid cohesion cohesin chromatin immunoprecipitation. INTRODUCTION Chromosomes are duplicated during S phase in a process that entails not only DNA replication but also replication of the chromatin itself. Thus the distribution and modification state ofnucleosomes as well as other .