Mads at the nuclear pore

Two recent studies in mammalian cells have shown that spindle checkpoint proteins can be found at the nuclear pore during interphase and that nucleoporins localize to kinetochores during mitosis. A new study on page 807 by Iouk et al. provides the first functional connection between kinetochores and nuclear pores through spindle checkpoint proteins and suggests that the two structures were linked long before vertebrates evolved.

Iouk et al. found budding yeast checkpoint proteins Mad1p and Mad2p at the nuclear pore complex (NPC). The Mad proteins interacted with a subcomplex of the NPC that contained, among other nucleoporins, Nup53p. The use of deletion strains indicated that Mad2p is linked to the NPC by its association with Mad1p, which in turn is bound to the Nup53p-containing complex. Unlike in vertebrates, which break down the nuclear envelope...