Cohesins are protein complexes with roles in chromosome biology, specifically in the maintenance of chromosome structure. These complexes are best known for their ability to hold sister chromatids together after DNA replication and in facilitating chromosome segregation during cell division. Cohesin complexes physically encircle sister chromatids, holding them together. This process involves the binding of cohesin subunits, such as SMC1 (Structural Maintenance of Chromosomes 1) and SMC3, to specific sites on the chromatin, forming a ring-like structure.Cohesin-mediated sister chromatid cohesion ensures that replicated DNA molecules are held together until the appropriate time for chromosome segregation during mitosis or meiosis. Without cohesins, premature separation of sister chromatids could lead to chromosome mis-segregation. Cohesin complexes contribute to chromosome condensation, promoting higher-order chromatin folding. They also help bring distant chromatin regions into proximity, influencing the overall structure of chromosomes. This role of cohesins is important during mitosis since by compacting chromatin chromosomes are more easily segregated into daughter cells during cell division. Cohesin complexes can also play a role in gene regulation by influencing the 3D organization of chromatin. They contribute to the formation of chromatin loops that bring enhancers, promoters, and regulatory elements into proximity. Cohesin-mediated chromatin looping is essential for facilitating long-range interactions between distant regulatory elements and target genes. This 3D organization allows for coordinated gene expression by ensuring that enhancers and promoters are in proximity. Cohesins have also been implicated in DNA repair and recombination processes. They can interact with proteins involved in these pathways and facilitate the assembly of repair foci at DNA damage sites. Cohesin-mediated DNA repair ensures that damaged DNA is properly repaired, maintaining genomic integrity. It helps coordinate the recruitment and activity of repair factors at the site of DNA damage. Cohesins, along with other proteins like CTCF (CCCTC-Binding Factor), can also create boundaries between chromatin domains. They help establish insulator elements that separate regions with different chromatin states. These boundary elements play a role in correct segregation of chromosomes during cell division. By demarcating distinct chromatin domains, cohesins and boundary elements help prevent the spreading of epigenetic marks and maintain the integrity of functional genomic regions. Cohesin complexes have specific functions during meiosis, where homologous chromosomes segregate. In meiosis I, cohesins are protected at centromeres until they are cleaved, allowing homologous chromosomes to separate. In meiosis II, cohesin cleavage at centromeres and along chromatids ensures the separation of sister chromatids. The regulation of cohesin cleavage during meiosis is critical for ensuring the accurate segregation of chromosomes. Cohesin dynamics in meiosis are tightly controlled and allow for the unique chromosome behaviour required for sexual reproduction. Cohesin loading onto chromosomes is mediated by the SMC1/SMC3 heterodimer and associated proteins such as SCC2 (also known as NIPBL). Cohesin unloading is controlled by the protease separase, which cleaves the SMC1/SMC3 subunits at the onset of anaphase.The precise loading and unloading of cohesins are crucial for the timing of chromosome segregation during mitosis and meiosis, with errors in these processes leading to chromosome mis-segregation and aneuploidy. We provide a wide product range of research tools for studying cohesins, including Rad21 antibodies, SMC1 antibodies, Securin antibodies, and Shugoshin antibodies. Explore our full cohesin product range below and discover more, for less.