The role of clathrin in mitotic spindle organisation.

Clathrin, a protein best known for its role in membrane trafficking, has been recognised for many years as localising to the spindle apparatus during mitosis, but its function at the spindle remained unclear. Recent work has better defined the role of clathrin in the function of the mitotic spindle and proposed that clathrin crosslinks the microtubules (MTs) comprising the kinetochore fibres (K-fibres) in the mitotic spindle. This mitotic function is unrelated to the role of clathrin in membrane trafficking and occurs in partnership with two other spindle proteins: transforming acidic coiled-coil protein 3 (TACC3) and colonic hepatic tumour overexpressed gene (ch-TOG; also known as cytoskeleton-associated protein 5, CKAP5). This review summarises the role of clathrin in mitotic spindle organisation with an emphasis on the recent discovery of the TACC3-ch-TOG-clathrin complex.