A new member joins the yeast filament party

Anovel yeast filament protein has been found. Martijn van Hemert, Paul van Heusden (Leiden University, Leiden, Netherlands), and colleagues have identified Fin1, which forms a filament only at a specific point in the cell cycle.

The group identified Fin1 in a screen for interaction partners of the 14-3-3 family of regulatory proteins. In nondividing cells, Fin1 is undetectable, whereas in small budded cells it localizes to the nucleus. As the cell cycle progresses, Fin1 forms a filament between the nuclei of dividing cells, extending between the spindle pole bodies. Fin1 also forms an intermediate filament in vitro and seems to act independently of tubulin. “It is the first time that someone has found a filament between spindle poles that is different from microtubules,” says van Heusden.

The only other known yeast intermediate filament is...