Central component of cohesin, a complex required for chromosome cohesion during the cell cycle. The cohesin complex may form a large proteinaceous ring within which sister chromatids can be trapped. At anaphase, the complex is cleaved and dissociates from chromatin, allowing sister chromatids to segregate. Cohesion is coupled to DNA replication and is involved in DNA repair. The cohesin complex plays also an important role in spindle pole assembly during mitosis and in chromosomes movement. Interacts with MXI1, MXD3 and MXD4. Interacts with SYCP2. Found in a complex with SMC1A, CDCA5 and RAD21, PDS5A/APRIN and PDS5B/SCC-112. Forms a heterodimer with SMC1A or SMC1B in cohesin complexes. Cohesin complexes are composed of the SMC1 (SMC1A or SMC1B) and SMC3 heterodimer attached via their hinge domain, RAD21 which link them, and one STAG protein (STAG1, STAG2 or STAG3), which interacts with RAD21. Also found in meiosis-specific cohesin complexes. Interacts with NUMA1, and forms a ternary complex with KIF3B and KIFAP3, suggesting a function in tethering the chromosomes to the spindle pole and in chromosome movement. Interacts with PDS5A and WAPAL; regulated by SMC3 acetylation. Belongs to the SMC family. SMC3 subfamily. Note: This description may include information from UniProtKB.
Molecular Function: identical protein binding; dynein binding; protein binding; protein heterodimerization activity; microtubule motor activity; ATP binding
Biological Process: meiosis; mitosis; sister chromatid cohesion; negative regulation of DNA endoreduplication; signal transduction; DNA repair; M phase of mitotic cell cycle; mitotic spindle organization and biogenesis; DNA mediated transformation; cell division; mitotic cell cycle; mitotic metaphase/anaphase transition; mitotic prometaphase; regulation of DNA replication
SS: The number of records in which this modification site was determined using site-specific methods. SS methods include amino acid sequencing, site-directed mutagenesis, modification site-specific antibodies, specific MS strategies, etc.