Characterization of AtSUN–AtWIP interactions. (A) Domain organization of AtWIP1 and mutant derivatives. AtWIP1 has an N-terminal domain with an unknown function (cyan), an NLS (blue), a CCD-binding AtRanGAP1 (red), a predicted TMD (yellow), and a PNS tail (shown in residues). (B) Domain organization of AtSUN2 and deletion constructs. AtSUN2 has an N-terminal domain with an unknown function (cyan), an NLS (blue), a TMD (yellow), an unknown domain (white), a CCD (red), and a SUN domain (here split to an N-terminal part [green] and a C-terminal part [orange]) (A and B) Figures are drawn to scale. (C) AtWIP1 interacts with AtSUN2 through its PNS tail. (D) AtWIP1, AtWIP2, and AtWIP3 interact with AtSUN2. (E) AtWIP1 interacts with AtSUN1 through its PNS tail. (F) AtWIP1, AtWIP2, and AtWIP3 interact with AtSUN1. (G) AtSUN2 interacts with AtWIP1 through its SUN domain. (C–G) GFP- or CFP-tagged proteins were immunoprecipitated and detected by anti-GFP antibody. RFP-Myc– or Myc-Flag–tagged proteins were detected by anti-Myc antibody, and RFP-Flag–tagged proteins were detected by anti-Flag antibody. The input/IP ratio is 1:10. Numbers on the left indicate molecular mass in kilodaltons.