Figure 4.

Nek1 and TAZ form a negative feedback loop in the regulation of PC2 levels. (A) 293T cells were transfected with Myc-tagged Nek1 along with GST or GST-TAZ. Western blot was performed for GST, Myc, and GAPDH. (B) Immunoprecipitation was performed with anti-Myc and immunoblotted for Nek1 with the cell extracts as described in Figure 4A. (C) 293T cells were cotransfected with Myc-Nek1 and GST or GST-TAZ. Forty hours after transfection, cells were treated with 10 mM MG132 for 4 hours. Western blots for Myc, GST, and GAPDH were done. (D) Myc-Nek1 was expressed along with GST, GST-tagged wild-type TAZ, or F-box deletion mutant of β-Trcp (β-Trcp-ΔF). Western blot shows that expression of β-Trcp-ΔF prevents Nek1 degradation. (E) Model of the feedback loop between Nek1 and TAZ in the regulation of PC2 (see text).