Fig. 4. EGFP-TPPP/p25 localization in transfected NRK cells at different stages of the cell cycle. Tubulin, TPPP/p25 and DNA are red, green and blue in the merged images, respectively. (A-D) At interphase TPPP/p25 localizes over the microtubules throughout the cell, but accumulates at a higher levels in the vicinity of the centrosome (green dominates in the merged image D). (F and J) From prophase (not shown) to late anaphase, free TPPP/p25 level is considerably higher in the cytoplasm. In metaphase (E-H) and anaphase (I-L) TPPP/p25 accumulation is detectable only over the spindle microtubules and the centrosomes. (M-P) The level of free TPPP/p25 decreases again at the telophasecytokinesis transition and TPPP/p25 becomes preferentially enriched over the microtubules spanning the cytokinetic cleavage furrow.