What is the function of condensins?
Condensins are large protein complexes that play a central role in chromosome assembly and segregation during mitosis and meiosis (Figure 1). Their subunits were originally identified as major components of mitotic chromosomes assembled in Xenopus egg extracts.
What do cohesin proteins do?
Cohesin is a chromosome-associated multisubunit protein complex that is highly conserved in eukaryotes and has close homologs in bacteria. Cohesin mediates cohesion between replicated sister chromatids and is therefore essential for chromosome segregation in dividing cells.
Are Cohesins and condensins SMC proteins?
In eukaryotes, two different SMC protein complexes, condensin and cohesin, regulate chromosome condensation and sister chromatid cohesion, respectively.
What is the role of cohesin proteins in cell division?
Cohesin proteins and cell division Cohesin proteins play a critical role in cell division during mitosis. After the chromosomes are replicated, they line up along the middle of the cell and then are pulled to the 2 opposite ends of the cell, allowing the cell to divide down the middle.
What happens if there is no cohesin?
Without cohesin, the cell would be unable to control sister chromatid segregation since there would be no way of ensuring whether the spindle fiber attached on each sister chromatid is from a different pole. 2. It facilitates spindle attachment onto chromosomes.
What does cohesin do in cell division?
Cohesion at the centromeres ensures biorientation of chromatids on the spindle and accurate segregation during meiosis II, as in mitosis. The destruction of centromeric sister chromatid cohesion triggers their disjunction and segregation to opposite poles of the cell, yielding haploid cells.
Are SMC proteins long and flexible?
SMC proteins are large (approximately 110 to 170 kDa), and each is arranged into five recognizable domains (Figure 1). Rotary shadowing electron microscopy of several SMC dimers has shown that each has amino- and carboxy-terminal globular domains, separated by a rod with a central, flexible hinge .