| Annotated protein: | BTB/POZ domain-containing protein KCTD12 (Pfetin) (Predominantly fetal expressed T1 domain). Gene symbol: KCTD12. Taxonomy: Mus musculus (Mouse). Uniprot ID: Q6WVG3 |
| antibody wiki: | |
| SynGO gene info: | SynGO data @ KCTD12 |
| Ontology domain: | Biological Process |
| SynGO term: | G protein-coupled neurotransmitter receptor activity involved in regulation of presynaptic membrane potential (GO:0150047) |
| Synapse type(s): | hippocampus, GABAergic |
| Annotated paper: | Schwenk J, et al. "Native GABA(B) receptors are heteromultimers with a family of auxiliary subunits" Nature. 2010 May 13;465(7295):231-5 PMID:20400944 |
| Figure(s): | Figure 1, 3, 4 |
| Annotation description: | Figure 1: identification of KCTD8, KCTD12, KCTD12B and KCTD16 as subunits of native GABAB receptors by AP+ MS of both GABAB1 and GABAB2 receptors. No KCTD-specific peptides were detected in affinity purifications with anti-GABAB1 and anti-GABAB2 from brains of GABAB1 and GABAB2 knockout mice, respectively. Co-assembly of the identified KCTD proteins with native GABAB receptors was further corroborated by reverse affinity purifications (Supplementary Fig. 3C + 6), western blot analysis of native gel separations of brain membrane fractions (Fig. 1C) and affinity purifications of membrane fractions of HEK293 cells expressing various combinations of differentially tagged GABAB1, GABAB2 and KCTD12 proteins (Supplementary Fig. 7a) Figure 3a: current traces recorded in whole oocytes from heteromeric Kir3.1/3.2 channels in response to 60-s applications of GABA to GABAB receptors assembled from GABAB1 and GABAB2 (GABAB) either alone or in combination with KCTD proteins (GABAB1KCTDx). The responses of GABAB1 KCTD12 receptors showed pronounced desensitization. Supplementary Fig. 10: the KCTD12-induced desensitization was specific for GABAB receptors and was not observed when GABAB2(Y902A), a mutant precluding KCTD binding, was co-assembled into the receptor complexes. Figure 4a-b: Experiments in CHO cells co-expressing GABAB, Kir3.1/3.2 channels and the different KCTD proteins. GABAB-activated Kir3 currents elicited by 25-s applications of baclofen closely recapitulated the pronounced differences in kinetics and extent of desensitization seen in oocytes. Figure 4c: In addition to their impact on the kinetics, KCTD12 significantly influences the agonist concentration dependence of the GABAB responses as determined by apparent dose- response relationships with baclofen Figure 4d: the KCTD effects were examined in cultured hippocampal neurons. On transfection with the four KCTD proteins, a significant increase in steady-state desensitization was obtained with KCTDs 12 and 12b only. Moreover, KCTDs 12 and 12b also induced a significant decrease in the 20-80% rise time Supplementary Fig. 13: These effects of KCTD proteins on GABAB receptors in hippocampal neurons were corroborated by a dominant-negative transgenic approach and short hairpin RNA (shRNA)-mediated knockdown of KCTD protein. Taken together, the paper demonstrates that KCTD proteins endow GABAB receptors with subtype-specific properties of their G-protein signalling, regulating the the activity of voltage-gated calcium and inward-rectifier potassium channels. As KCTD12, GABAB receptors, Kir3 channels and CaV channels all localize to both the pre- and postsynaptic membrane, the GO-term "G protein-coupled neurotransmitter receptor activity involved in regulation of presynaptic membrane potential" was selected, as well as "G protein-coupled neurotransmitter receptor activity involved in regulation of postsynaptic membrane potential" (annotation #5576) |
| Evidence tracking, Biological System: | Cultured neurons Non-neuronal tissue Intact tissue |
| Evidence tracking, Protein Targeting: | RNAi / shRNA Over-expression |
| Evidence tracking, Experiment Assay: | Electrophysiology (generic) IP + WB/MSMS |
| Annotator(s): | Robin Clement Guus Smit Matthijs Verhage |
| ORCID: | 0000-0002-2286-1587 0000-0002-2514-0216 |
| Lab: | Department of Functional Genomics, Department of Molecular and Cellular Neurobiology, Center for Neurogenomics and Cognitive Research, Vrije Universiteit Amsterdam, 1081 HV Amsterdam, The Netherlands |
| SynGO annotation ID: | 5572 |
| Dataset release (version): | 20231201 |
| View annotation as GO-CAM model: |  |