Substrate-specific adapter of a BCR (BTB-CUL3-RBX1) E3 ubiquitin ligase complex that acts as a regulator of ion transport in the distal nephron (PubMed:14528312, PubMed:22406640, PubMed:23387299, PubMed:23453970, PubMed:23576762, PubMed:23665031). The BCR(KLHL3) complex acts by mediating ubiquitination of WNK4, an inhibitor of potassium channel KCNJ1, leading to WNK4 degradation (PubMed:23387299, PubMed:23453970, PubMed:23576762, PubMed:23665031). The BCR(KLHL3) complex also mediates ubiquitination and degradation of CLDN8, a tight-junction protein required for paracellular chloride transport in the kidney (By similarity). Protein modification; protein ubiquitination. Homodimer (PubMed:28052936). Component of the BCR(KLHL3) E3 ubiquitin ligase complex, at least composed of CUL3 and KLHL3 and RBX1 (Probable) (PubMed:23453970, PubMed:23576762, PubMed:23573258). Interacts with SLC12A3 (PubMed:22406640). Interacts with WNK1 and WNK4 (PubMed:23387299, PubMed:23453970, PubMed:23573258, PubMed:23576762, PubMed:23665031, PubMed:26435498, PubMed:27727489). Interacts with CLDN8 (By similarity). Widely expressed. Phosphorylation at Ser-433 by PKA decreases the interaction with WNK4, Leading to inhibit WNK4 degradation by the BCR(KLHL3) complex (PubMed:26435498, PubMed:27727489). Phosphorylation at Ser-433 is increased by insulin (PubMed:26435498). The disease is caused by variants affecting the gene represented in this entry. The BCR(KLHL3) complex was initially thought to act by mediating ubiquitination of SLC12A3/NCC (PubMed:22406640). However, it was later shown that effects on SLC12A3/NCC are indirect and caused by impaired ubiquitination of WNK4 (PubMed:23387299). Extended N-terminus.