Cohesine

Cohesins are protein complexes that are crucial in the cell, as well as in mitosis and meiosis .

Cohesin molecules stabilize the chromate structure in the cell and thus the three-dimensional structure of the chromosomes . During the replication of the DNA in the S phase of the cell cycle, the two sister chromatids are bound to one another along their entire length with the help of the Cohesin "rings". In the anaphase ( mitosis ), an enzyme , the separase , dissolves these cohesins again and the sister chromatids can be drawn by the spindle fibers to the cell poles. In higher eukaryotes , the cohesin is removed along the chromosome arms at the beginning of mitosis by phosphorylation by polo-like kinase 1 .

In meiosis , in addition to the sister chromatids described above, the cohesins also connect the homologous chromosomes in tetrad formation in prophase I. Here, the homologous chromosomes are separated in the anaphase of the first meiosis.

Individual evidence

1. ↑ Antonio Tedeschi, Gordana Wutz, Sébastien Huet, Markus Jaritz, Annelie Wuensche, Erika Schirghuber, Iain Finley Davidson, Wen Tang, David A. Cisneros, Venugopal Bhaskara, Tomoko Nishiyama, Alipasha Vaziri, Anton Wutz, Jan Ellenberg, Jan-Michael Peters : Wapl is an essential regulator of chromatin structure and chromosome segregation. . In: Nature . 501, No. 7468, September 15, 2013, pp. 3089-3114. doi : 10.1038 / nature12471 . PMID 23975099 . Retrieved November 20, 2013.
2. ^ Jan-Michael Peters, Antonio Tedeschi, Julia Schmitz: The cohesin complex and its roles in chromosome biology . In: Genes & Development . 22, No. 22, November 15, 2008, pp. 3089-3114. doi : 10.1101 / gad.1724308 . PMID 19056890 .