Its interaction with CUL3 suggests that it may act as a substrate adapter in some E3 ligase complex (PubMed:18573101). Does not affect the function of Kv channel Kv2.1/KCNB1, Kv1.2/KCNA2, Kv4.2/KCND2 and Kv3.4/KCNC4 (PubMed:19361449). {ECO:0000269|PubMed:18573101, ECO:0000269|PubMed:19361449}. This is the function of KCTD5 (potassium channel tetramerization domain containing 5, ENSG00000167977).