Fig. 4.

Identification of WNK4 domains that contribute to BK α-subunit degradation. A: schematic representation of WNK4 domains. Approximate location is shown of kinase domain (black), autoinhibitory domain (dark gray), and coiled coil (cc) domains (gray). B: effect of WNK4 truncations on BK α-subunit whole cell expression. HEK293 cells were transfected with myc-tagged BK α-subunit and GFP (control), or myc-tagged BK α-subunit with either WT or truncated WNK4 constructs. Whole cell lysates were subjected to IB with an anti-myc antibody to detect BK α-subunit or with an anti-actin antibody. Representative immunoblots are shown. C: summary of relative BK α-subunit whole cell expression normalized to whole cell actin levels (n = 5–6, ***P < 0.001, ANOVA followed by Tukey's multiple comparison test). Immunoblots were quantified as described in materials and methods.