| 2000 |
RIBEYE, a major component of synaptic ribbons, consists of a unique A domain that mediates assembly into large ribbon structures, and a B domain identical to CtBP2 that binds NAD+ with high affinity, similar to 2-hydroxyacid dehydrogenases. The A domain drives ribbon assembly while the B domain (CtBP2) provides NAD(H)-binding scaffolding function. |
Partial purification of synaptic ribbons, protein domain analysis, NAD+ binding assays, cDNA cloning |
Neuron |
High |
11163272
|
| 2005 |
Acetylation of CtBP2 by the nuclear acetyltransferase p300 at Lys-10 in its unique N-terminal domain is critical for nuclear localization. A K10R mutant is predominantly cytoplasmic due to enhanced nuclear export (sensitive to leptomycin B), and cytoplasmic localization of K10R correlates with enhanced repression of the E-cadherin promoter. |
Mutagenesis, subcellular fractionation, immunofluorescence, leptomycin B treatment, luciferase reporter assays |
The Journal of biological chemistry |
High |
16356938
|
| 2004 |
CtBP2 co-repressor function requires NADH-dependent homodimerization; mutations at Gly189 in the NAD+-binding fold abrogate dimerization and dramatically reduce co-repressor activity. Mutations at Arg272 (substrate-binding domain) and His321 (catalytic domain) also reduce co-repressor activity. A novel N-terminal repression domain distinct from the dehydrogenase domain was identified. |
Site-directed mutagenesis, transcriptional reporter assays, co-immunoprecipitation, deletion analysis |
Nucleic acids research |
High |
15037661
|
| 2020 |
Cryo-EM structures of CtBP2 demonstrate that the native state of CtBP2 in the presence of NADH is tetrameric. Tetramer-destabilizing mutants are defective for cell migration, transcriptional repression of E-cadherin, and activation of TIAM1, establishing the tetramer as the functional oligomeric form. |
Cryo-electron microscopy, cell migration assays, transcriptional reporter assays, mutagenesis |
Structure |
High |
33264605
|
| 2022 |
Analytical ultracentrifugation confirmed that CtBP1 and CtBP2 assemble into tetramers in the presence of saturating NAD+ or NADH, with tetramer-to-dimer dissociation constants of ~100 nM. Isothermal titration calorimetry showed NAD(H) binding dissociation constants of 30–500 nM depending on nucleotide and paralog, suggesting CtBP is fully saturated with NAD+ under physiological concentrations. |
Analytical ultracentrifugation, isothermal titration calorimetry |
FEBS letters |
High |
34997967
|
| 2021 |
CtBP2 repressor activity is reciprocally regulated by NADH (which promotes dimerization and repression) and acyl-CoAs (including malonyl-CoA, which shifts CtBP2 toward monomeric configuration and enhances interaction with PPARα to repress fatty acid oxidation). CtBP2 directly represses FoxO1-mediated hepatic gluconeogenesis and indirectly represses SREBP1-mediated lipogenesis. The Rossmann fold metabolite-sensing pocket is the critical structural domain. |
Liver-specific knockout mice, gene expression analysis, protein-protein interaction assays, structural analysis, in vitro binding assays |
Nature communications |
High |
34728642
|
| 2008 |
RIBEYE self-associates through five distinct interaction sites: three in the A-domain (mediating A-A homodimerization and A-B heterodimerization) and two in the B-domain (CtBP2). The B-domain homodimerization interface is topographically distinct from the A-domain docking site, and NAD+ negatively regulates the A-domain docking on the B-domain. Heterologously expressed RIBEYE forms ribbon-like aggregates that co-assemble with bassoon. |
Yeast two-hybrid, pulldown assays, synaptic ribbon interaction assays, coaggregation experiments, transmission electron microscopy, immunogold EM |
The Journal of neuroscience |
High |
18685021
|
| 2005 |
Direct physical interaction between RIBEYE (B domain/CtBP2) and Bassoon links the ribbon-associated compartment to the active zone compartment; loss of Bassoon causes ribbons to float freely in the cytoplasm rather than anchoring to the presynaptic membrane. |
Bassoon-deficient mice, immunofluorescence, co-immunoprecipitation, subcellular fractionation |
The Journal of cell biology |
High |
15728193
|
| 2016 |
RIBEYE is essential for synaptic ribbon formation: full deletion of RIBEYE in mice abolishes all presynaptic ribbons in retinal synapses. Loss of RIBEYE severely impairs fast and sustained neurotransmitter release at bipolar neuron/AII amacrine cell synapses and renders spontaneous miniature release sensitive to slow Ca2+-buffer EGTA, indicating RIBEYE mediates nano-domain coupling of Ca2+ channels to synaptic vesicle exocytosis. |
RIBEYE knockout mice, paired electrophysiological recordings in acute retina slices, EGTA sensitivity assays |
The EMBO journal |
High |
26929012
|
| 2011 |
Ribeye is required for presynaptic CaV1.3a calcium channel clustering at hair cell synapses and for stabilizing afferent neuron contacts. Ribeye knockdown reduces stimulus-evoked action potentials and causes loss of CaV1.3a channel clusters; overexpression of Ribeye causes ectopic CaV1.3a channel co-localization with Ribeye aggregates. |
Zebrafish morpholino knockdown, transgenic overexpression, immunofluorescence, electrophysiology |
Development |
High |
21350006
|
| 2006 |
The unique N-terminal amino acids 4–14 of CtBP2 direct it to an almost exclusively nuclear distribution in a p300 acetyltransferase-dependent manner (nuclear retention sequence). CtBP1 can be recruited to the nucleus through heterodimerization with CtBP2. The region a.a. 120–445 can also independently promote CtBP2 nuclear accumulation. |
Deletion mutagenesis, subcellular localization by immunofluorescence, heterologous domain fusion constructs, co-immunoprecipitation |
BMC cell biology |
Medium |
16999872
|
| 2002 |
Ctbp2-null mice die by E10.5 with defects in axial patterning and aberrant extraembryonic development. Compound Ctbp1/Ctbp2 mutants show dosage-sensitive defects in a broad range of developmental processes, with strong genetic interaction indicating overlapping roles in transcriptional repression. CtBP-deficient cells show compromised transcriptional repression activity. |
Gene-targeted knockout mice, transcription assays in CtBP-deficient cells, genetic epistasis analysis |
Molecular and cellular biology |
High |
12101226
|
| 2013 |
CCNH/CDK7 complex interacts with CtBP2 in vivo and in vitro and stabilizes CtBP2 by competing with tumor suppressor HIPK2 for CtBP2 binding, thereby inhibiting HIPK2-mediated phosphorylation and dimerization of CtBP2. Phosphorylation-defective CtBP2 interacts more strongly with CCNH/CDK7 and is more resistant to proteasomal degradation. CtBP2 promotes cancer cell invasion/migration in a CCNH-dependent manner. |
Co-immunoprecipitation in vivo and in vitro, CDK7/CCNH knockdown, proteasome inhibition assays, cell invasion/migration assays |
The Journal of biological chemistry |
Medium |
23393140
|
| 2012 |
CtBP2 promotes cancer cell migration via transcriptional activation of Tiam1 (a Rac GEF). CtBP2 occupies the Tiam1 promoter in a KLF8-dependent manner, and RNAi-mediated knockdown of CtBP2 reduces Tiam1 expression while overexpression increases it. Tiam1 is a key downstream mediator of CtBP2-mediated cell migration. |
RNA interference, overexpression, luciferase reporter assays, chromatin immunoprecipitation, cell migration assays |
Genes & cancer |
Medium |
23264848
|
| 2009 |
CtBP1/2 act as corepressors of C/EBPα at visceral white adipose gene promoters (resistin, angiotensinogen) in response to PPARγ ligand activation. C/EBPα recruits CtBP1/2 to these gene promoters, and this recruitment depends on critical residues in PPARγ helix 7. |
Chromatin immunoprecipitation, transcription reporter assays, siRNA knockdown, mutation of PPARγ helix 7 |
Molecular and cellular biology |
Medium |
19564408
|
| 1999 |
CtBP2 binds to deltaEF1 (ZEB family transcription factor) via the PLDLSL motif in the medial region of deltaEF1. CtBP2 fused to Gal4DBD acts as a transcriptional repressor, and CtBP2/CtBP1 serve as corepressors enhancing deltaEF1-mediated repression in a PLDLSL-dependent manner. |
Yeast two-hybrid screen, co-immunoprecipitation, Gal4 transcription reporter assays, mutagenesis of PLDLSL motif |
Molecular and cellular biology |
High |
10567582
|
| 2009 |
NGF promotes interaction between CtBP2 and acinus via Akt-mediated phosphorylation of acinus, leading to repression of cyclin A1 (but not cyclin A2) transcription. Overexpression of CtBP2 diminishes cyclin A1 transcription; depletion of CtBP2 abolishes NGF's suppressive effect on cyclin A1 expression. |
Co-immunoprecipitation, siRNA knockdown, overexpression, transcriptional reporter assays, phosphorylation assays |
Oncogene |
Medium |
19668232
|
| 2008 |
Munc119 is recruited to synaptic ribbons through direct interaction with the NAD(H)-binding region of RIBEYE(B) domain (CtBP2). The PrBP/delta homology domain of Munc119 mediates this interaction, which is independent of NADH binding. A RIBEYE point mutant (RE(B)E844Q) that cannot interact with Munc119 still binds NADH. |
Yeast two-hybrid, pulldown assays, co-immunoprecipitation, immunogold EM, site-directed mutagenesis |
The Journal of biological chemistry |
High |
18664567
|
| 2014 |
ArfGAP3 is a component of the photoreceptor synaptic ribbon complex that interacts with RIBEYE(B) domain (CtBP2) in an NAD(H)-dependent, redox-sensitive manner: NADH promotes and NAD+ inhibits the interaction. RIBEYE competes with Arf1 for ArfGAP3 binding. Overexpression of ArfGAP3 inhibits endocytotic vesicle uptake (FM1-43) in photoreceptors. |
Multiple independent interaction assays, redox manipulation, overexpression, FM1-43 uptake assay in photoreceptors |
The Journal of neuroscience |
High |
24719103
|
| 2009 |
ZEB1 cooperates with CtBP2 and HDAC1 to repress IL-2 promoter activity. This repression depends on the ZEB1-binding site at -100 in the IL-2 promoter and on the Pro-X-Asp-Leu-Ser (PXDLS) motif in CtBP2 for ZEB1 interaction. Chromatin immunoprecipitation shows ZEB1 binding to the IL-2 promoter. |
Luciferase reporter assays, chromatin immunoprecipitation, overexpression, mutagenesis of PXDLS motif |
International immunology |
Medium |
19181930
|
| 2006 |
E1A displaces histone methyltransferase G9a and the E-box repressor ZEB from the CtBP2 complex and enhances acetylation of CtBP2 by recruiting p300 to the CtBP2 complex. CtBP2, but not CtBP1 isoforms, efficiently inhibits E1A transcriptional activation through its unique N-terminal domain in a manner independent of histone deacetylases. |
Co-immunoprecipitation, transcription assays, protein interaction studies |
The Journal of biological chemistry |
Medium |
17023432
|
| 2015 |
Ctbp2 facilitates exit from pluripotency in embryonic stem cells by: (1) associating with the NuRD complex to mediate H3K27 deacetylation at active ESC genes, and (2) enabling subsequent PRC2-mediated H3K27me3 at those same genes. Ablation of Ctbp2 sustains high H3K27ac and impedes H3K27me3, maintaining ESC gene expression during differentiation. |
ChIP-seq genome-wide analysis, co-immunoprecipitation, siRNA knockdown, histone modification analysis |
Stem cells |
Medium |
25944056
|
| 2017 |
Ctbp2 associates with major components of the β-catenin destruction complex in ESCs and limits β-catenin accessibility to core pluripotency transcription factors. Ctbp2 knockdown stabilizes β-catenin, which then interacts with core pluripotency factors normally occupied by Ctbp2, leading to incomplete exit from pluripotency. |
Co-immunoprecipitation, siRNA knockdown, ChIP assays, protein stability analysis |
Experimental & molecular medicine |
Medium |
29026198
|
| 2013 |
CTBP2 acts as a coactivator of RAR/RXR nuclear receptors in retinoic acid signaling, associating with RAR/RXR at RA target gene promoters and recruiting the histone acetyltransferase p300 to create a chromatin environment permissive for transcription. CTBP2 suppression confers resistance to RA-induced differentiation. |
RNAi genetic screen, ChIP assays, co-immunoprecipitation, differentiation assays |
Molecular and cellular biology |
Medium |
23775127
|
| 2014 |
CtBP2 interacts with the transcription factor E2F7 through a canonical PIDLS CtBP-binding motif located in E2F7's hydrophobic cleft-interacting region. E2F7 represses E2F1 transcription and inhibits cell proliferation in a CtBP-dependent manner, establishing CtBP2 as a corepressor of E2F7. |
Proteomic (mass spectrometry) interactome analysis, co-immunoprecipitation, transcription reporter assays, cell proliferation assays |
Genes & cancer |
Medium |
24955216
|
| 2011 |
cAMP/PKA signaling promotes CtBP2 (but not CtBP1) degradation via HIPK2, leading to de-repression of Mitf and REST expression and induction of melanocyte differentiation in neural crest cells. Knockdown of HIPK2 increases CtBP2 levels, suppresses Mitf/REST, reduces melanocyte differentiation, and increases sympathoadrenal lineage differentiation. |
Knockdown in NC cultures and zebrafish, PKA inhibition, proteasome inhibition, lineage differentiation assays |
Molecular and cellular biology |
Medium |
21199918
|
| 2015 |
HIPK2 phosphorylates CtBP2 at serine 428, and this phosphorylation strengthens the interaction between KLF3 and CtBP2, increasing transcriptional repression by KLF3. Mass spectrometry identified S428 as the phosphorylation site on CtBP2. |
Mass spectrometry identification of phosphorylation site, mutagenesis, co-immunoprecipitation, transcription reporter assays |
The Journal of biological chemistry |
Medium |
25659434
|
| 2014 |
CtBP2 directly binds acireductone dioxygenase (ARD1) through ALDOB acting as a scaffold, and ARD1 catalyzes synthesis of an endogenous CtBP2 inhibitor (4-methylthio 2-oxobutyric acid) that inhibits CtBP2 activity. ALDOB-CtBP2 interaction-dependent mechanism suppresses CtBP2-mediated repression of cell cycle inhibitors, pro-apoptotic and epithelial marker genes. |
Co-immunoprecipitation, mass spectrometry, overexpression/knockdown studies, xenograft tumor models |
Frontiers of medicine |
Low |
36790589
|
| 2020 |
CtBP2 forms a transcriptional complex with histone acetyltransferase p300 and AP-1 subunits (c-Jun and c-FOS) that binds the TGFB1 promoter and activates TGF-β expression. Mass spectrometry and co-immunoprecipitation identified this complex. Knockdown or blockage of CtBP2 decreased p300 and AP-1 occupancy at the TGFB1 promoter. |
Mass spectrometry, co-immunoprecipitation, chromatin immunoprecipitation, siRNA knockdown |
International journal of biological sciences |
Medium |
31929749
|
| 2018 |
CtBP2 forms a complex with p300 and Runx2 that represses bone formation genes (OSC, ALPL, COL1A1, IBSP, SPP1, MMP13) when NADH levels are low. Low NADH disrupts CtBP2 dimerization, enhancing blockage of p300-Runx2 complex accessibility to target gene promoters. Forced increase of NADH (CoCl2) reverses this repression. |
Mass spectrometry, co-immunoprecipitation, ChIP assays, NADH manipulation, gene expression analysis |
International journal of biological sciences |
Medium |
30585266
|
| 2019 |
CtBP2 directly interacts with OCT1 (POU2F1) to form a transcriptional complex that orchestrates the EMT program. Mutation of the CtBP-binding motif in OCT1 diminishes its ability to promote EMT. TGF-β promotes formation of the CtBP2/OCT1 complex. |
Co-immunoprecipitation, mutagenesis of CtBP-binding motif in OCT1, EMT marker expression analysis |
Biochemical and biophysical research communications |
Low |
31866012
|
| 2023 |
CTBP2 is identified as a cofactor of PCIF1 (m6Am methyltransferase) that catalyzes m6Am deposition on mRNA caps. CTBP2 binds similar mRNAs as PCIF1 (CLIP-Seq), and knockout of CTBP2 reduces PCIF1 occupancy on TET2 mRNA; the PCIF1-CTBP2 complex negatively regulates translation of TET2 mRNA. |
CLIP-Seq, m6Am-Seq, co-immunoprecipitation, CTBP2 knockout, translation assays |
The Journal of clinical investigation |
Medium |
37643007
|
| 2021 |
CtBP2 forms transcriptional complexes with NRF1 and NRF2 that are required to promote expression of antioxidant genes in response to oxidative insults. CtBP2 is identified as an obligate partner of NRF1/NRF2 for antioxidative defense gene transcription. |
Co-immunoprecipitation, gene expression analysis under oxidative stress, CtBP2 knockdown/overexpression |
Biochemical and biophysical research communications |
Low |
34052660
|
| 2023 |
Malonyl-CoA (increased in obese tissues) binds CtBP2 Rossmann fold and shifts its conformational equilibrium toward monomers, enhancing interaction with PPARα and repressing fatty acid oxidation. Mutations favoring monomeric CtBP2 increase CtBP2-PPARα interaction; liver-specific CtBP2 deletion derepresses PPARα target genes. |
Mutagenesis, protein-protein interaction assays, liver-specific knockout mice, metabolic manipulation of malonyl-CoA |
The Journal of biological chemistry |
Medium |
37286039
|
| 2019 |
ZEB1 interaction with CTBP2 in the embryonic cerebral cortex is required for ZEB1 to elicit its effect on the multipolar-to-bipolar transition of differentiating neurons (cell migration), but is not required for ZEB1 suppression of Neurod1 (neuronal differentiation). Overexpression of Zeb1 blocks NPC lineage progression and causes subcortical heterotopia. |
In utero electroporation, co-immunoprecipitation, neuronal migration/differentiation assays in vivo |
Cell reports |
Medium |
31116980
|
| 2024 |
EVI1 requires interaction with CTBP1 and CTBP2 via a single PLDLS motif for leukemic transformation in 3q26/MECOM-rearranged AML. A 4× PLDLS repeat construct that outcompetes EVI1 binding to CTBP1/2 inhibits AML cell proliferation in vitro and in xenotransplant models. |
Protein folding predictions, proteomics, competitive PLDLS constructs, in vitro proliferation assays, xenotransplant models |
Science advances |
High |
38748792
|
| 2017 |
RIBEYE(B) domain (CtBP2) directly interacts with lipid components of synaptic vesicles (particularly lysophospholipids) in an NAD(H)-dependent, redox-sensitive manner: NADH (reduced form) enhances binding while NAD+ (oxidized form) inhibits it. This was demonstrated using liposome sedimentation assays and synaptic vesicle-containing membrane fractions. |
Liposome sedimentation assays, synaptic vesicle membrane fractions, defined lipid composition liposomes, NADH/NAD+ manipulation |
The Biochemical journal |
Medium |
28202712
|
| 2022 |
The RIBEYE B-domain (CtBP2) is essential for stability of the RIBEYE A-domain and for synaptic ribbon assembly. Knockin mice in which the B-domain was replaced by a fluorescent protein showed destabilization of the hybrid protein and complete loss of synaptic ribbons, despite intact A-domain. |
Knockin mouse genetics, electron microscopy, immunofluorescence, protein stability analysis |
Frontiers in molecular neuroscience |
High |
35153673
|
| 2014 |
Zscan4 protein interacts directly with LSD1 and CtBP2 in mouse embryonic stem cell nuclei, as demonstrated by protein interaction analyses, suggesting Zscan4 may regulate gene transcription through these interactions. |
Co-immunoprecipitation, proximity ligation assay in ESC nuclei, GAL4-fusion transcription reporter assays |
PloS one |
Low |
24594919
|
| 2013 |
CtBP2 represses tumor-suppressor genes (NCOR, RIP140) and AR corepressors in prostate cancer cells by binding with androgen receptor (AR) to promoter enhancers of these genes. Global gene expression analysis revealed CtBP2 silencing increases AR interactions with corepressors and limits histone modification. |
ChIP assays, RNAi, global gene expression analysis, xenograft tumor model |
Cancer research |
Medium |
25228652
|
| 2021 |
CtBP2 co-activates insulin gene expression in pancreatic β cells by interacting with NEUROD1 and decompacting chromatin in the insulin gene promoter (established by global genomic mapping of CtBP2 binding sites). β cell-specific CtBP2-deficient mice manifest glucose intolerance with impaired insulin secretion. |
β cell-specific knockout mice, ChIP-seq genome-wide binding analysis, transcriptome analysis, glucose tolerance tests |
Cell reports |
High |
37557182
|