An update on cohesin function as a 'molecular glue' on chromosomes and spindles.

One of the critical events in mitosis is proper sister chromatid cohesion, which is mediated by a protein complex called cohesin. The cohesin complex is best known for its role in tethering the sister DNA molecules. This review summarizes recent progress in understanding the functions of cohesin, and of its major subunits, SMC1, SMC3, Scc1 and Scc3. It is now clear that cohesin also plays crucial roles in controlling transcription and gene expression, DNA damage repair and spindle pole formation; functions that are beyond the traditional view of cohesin as a 'molecular glue' that holds sister chromosomes together.