Substrate-adapter for CUL3-RING ubiquitin ligase complexes which mediates the ubiquitination and subsequent proteasomal degradation of TCHP, a protein involved in ciliogenesis down- regulation. Thereby, positively regulates ciliogenesis, playing a crucial role in the initial steps of axoneme extension (PubMed:25270598). May also play a role in endoplasmic reticulum calcium ion homeostasis (PubMed:25983243). . This is the function of KCTD17 (potassium channel tetramerization domain containing 17, Ensembl gene identifier ENSG00000100379).