Fig. 2.
Mislocalization of overexpressed and mutant Cid to euchromatin. (A) Overexpressed Cid-GFP localizes to both centromeres (arrowheads) and euchromatin in interphase cells and is incorporated into metaphase chromosomes in Drosophila Kc cells but not into the heterochromatic chromocenter (Left) (60). H3.3 is found in chromosome arms and rDNA (arrow) but is undetectable in heterochromatin and centromeres (Right). (B) GFP fusions with Cid from D. melanogaster and Drosophila pseudoobscura localize to D. melanogaster centromeres, whereas a GFP fusion with Cid from D. bipectinata shows a euchromatic distribution (80). (C) Swaps between segments of melanogaster (blue) and bipectinata (orange) Cid show that the 15-aa loop 1 segment alone is responsible for targeting (80). Single amino acid substitutions to glycine or alanine cause melanogaster Cid-GFP to display a euchromatic distribution (orange letters), where uppercase letters indicate mislocalization when expressed under both the Cid endogenous promoter and an induced heat shock promoter, and lowercase letters indicate when mislocalization occurred only with the induced heat shock promoter. [Reproduced with permission from ref. 39 (A Left), ref. 60 (A Right), and ref. 80 (B).]