Fig. 2. Localization of SIN proteins. The figure shows schematically the localization of SIN proteins and some of the regulators through the cell cycle. The data are taken from references cited in the text. The colored cutout within the nucleus in the localization sequence for S. pombe flp1 represents the nucleolus. In the S. pombe cells, the grey horizontal bar within them represents the mitotic spindle, while the short bar at the cell center represents the position of the contractile ring. The localization of Par1p is similar to that of Mob1p, whereas Scw1p is cytoplasmic throughout the cell cycle. There is also a significant cytoplasmic pool of Mob1p and Par1p that is not indicated, for reasons of clarity. It is noteworthy that signal intensity of some of the proteins at the spindle pole body varies significantly through the cell cycle. To convey this, the intensity has been assigned on a arbitrary scale of 1 (present, but very faint) to 5 (present, strongest signals observed). The absolute signal strengths vary from protein to protein, and so the numbers give no indication of the amounts of protein relative to each other.