GIPs and CENH3 colocalize and associate in the same protein complex. (A–E) Immunodetection of GIP1-GFP and CENH3 in gip1gip2 meristematic root cells. Confocal microscopy (A–C) shows that GIP1-GFP is present at the nuclear periphery (A) and at the spindle (B) and phragmoplast (C) during mitosis (arrows) as well as at the centromeres/kinetochores (arrowheads). Fluorescent profiles (A'–C') indicate the colocalization of both proteins at centromeres in interphase nuclei and mitotic cells. (D and E) Superresolution microscopy (SIM) reveals the colocalization of GIP1-GFP and CENH3 in both interphase nuclei (D) and prometaphase cells (E). (Insets) Magnification of the GIP1-CENH3 colocalization. Green, red, and blue axes indicate x, y, and z axes, respectively. (F) GIP1::GIP1-GFP is expressed in a gip1 line overexpressing YFP-CENH3. GIP1-GFP is present at centromeres and colocalizes with CENH3 but with at different relative intensities (filled arrowheads). Corresponding fluorescent profiles (empty arrowheads in F' and F″) indicate protein colocalization. (G) Coimmunoprecipitation of GIP1- or GIP2-GFP with endogenous CENH3 using anti-GFP antibodies. (Scale bars, 2 µm; Insets, 0.2 µm.)