| 2006 |
PLK1 phosphorylates PBIP1 (CENPU) at Thr-78, creating a self-tethering phosphopeptide motif that specifically binds the polo-box domain (PBD) of PLK1 (but not PLK2 or PLK3), recruiting PLK1 to interphase and mitotic kinetochores. Later in mitosis, PLK1 also induces PBIP1 degradation in a T78-dependent manner, enabling PLK1 to interact with other kinetochore components required for proper chromosome segregation. |
In vitro kinase assays, mutagenesis of T78, PBD-binding assays, live-cell imaging, spindle checkpoint assays |
Molecular cell |
High |
17081991
|
| 2005 |
CENP-50 (CENPU) is a constitutive centromere component that colocalizes with CENP-A and CENP-H throughout the cell cycle; its centromere localization depends on CENP-H and CENP-I. CENP-50 physically interacts with the CENP-H/CENP-I complex (shown by co-immunoprecipitation). Loss of CENP-50 causes prolonged mitosis and premature sister chromatid separation upon spindle checkpoint activation, indicating a role in recovery from spindle damage. |
Knockout in chicken DT40 cells, co-immunoprecipitation, immunofluorescence |
Molecular and cellular biology |
High |
16287847
|
| 2010 |
CENPU directly interacts with Hec1 (NDC80) at kinetochores. CENPU itself binds microtubules directly in vitro and displays cooperative microtubule-binding activity with Hec1. Aurora B phosphorylates CENPU, and this phosphorylation reduces kinetochore–microtubule interaction, contributing to Aurora B's error-correction function. shRNA-mediated knockdown of CENPU impairs kinetochore–microtubule attachment. |
Co-immunoprecipitation, in vitro microtubule-binding assays, in vitro Aurora B kinase assay, shRNA knockdown with mitotic phenotype analysis |
The Journal of biological chemistry |
High |
21056971
|
| 2011 |
PBIP1 (CENPU) directly interacts with CENP-Q, and this interaction is mutually required for their stability and centromere localization. PLK1 forms a ternary complex with PBIP1 and CENP-Q through the self-generated p-T78 motif on PBIP1, and PLK1-dependent phosphorylation of CENP-Q within this complex leads to delocalization of the PBIP1–CENP-Q complex from mitotic centromeres. |
Co-immunoprecipitation, in vitro PLK1 kinase assay, mutagenesis, immunofluorescence localization |
The Journal of biological chemistry |
High |
21454580
|
| 2015 |
PLK1 phosphorylates the CENP-Q subunit of the PBIP1–CENP-Q complex at multiple sites; phosphorylation of nine sites drives delocalization of the complex from kinetochores. Phospho-mimetic (9D/E) mutations prevent localization to interphase prekinetochores, while phospho-null (9A) mutations prolong kinetochore residence. Both mutants impair proper chromosome segregation, demonstrating that timely localization and delocalization of the PBIP1–CENP-Q complex are both critical for mitotic progression. PLK1-dependent delocalization indirectly leads to cytosolic degradation of PBIP1 and CENP-Q. |
In vitro PLK1 kinase assay, mutagenesis (9A and 9D/E), chromatin fractionation, immunofluorescence, chromosome segregation assay |
The Journal of biological chemistry |
High |
25670858
|
| 2020 |
BUB1 (outer kinetochore) and CENP-U (inner kinetochore) are the main PLK1 receptors at kinetochores. Both share a constellation of sequence motifs (a PP2A-docking motif and two PLK1-docking sites). PLK1 recruitment to CENP-U requires priming phosphorylation by CDK1 followed by PLK1 itself. The two PLK1-docking sites on CENP-U promote PLK1 dimerization. This was demonstrated by ectopic localization assays, in vitro reconstitution, and kinetochore localization studies. |
Ectopic localization assay, in vitro reconstitution of PLK1–CENP-U interaction, kinetochore localization studies, mutagenesis |
Molecular cell |
High |
33248027
|
| 2021 |
BUB1 and CENP-U redundantly recruit PLK1 to kinetochores to stabilize kinetochore–microtubule attachments. CENP-U is recruited to kinetochores by the CENP-P and CENP-Q subunits of the CENP-O complex. Depletion of both BUB1 and CENP-U causes chromosome mis-segregation; depletion of either alone is insufficient, demonstrating functional redundancy. Cells depleted of BUB1 or CENP-U are sensitized to PLK1 inhibition but not Aurora B inhibition. Unlike its budding yeast homolog, the CENP-O complex does not regulate centromeric localization of Aurora B in human cells. |
Stable depletion by siRNA/shRNA, epistasis analysis (double depletion), chemical inhibitor sensitization assays, immunofluorescence |
Cell reports |
High |
34551298
|
| 2004 |
CENPU (MLF1IP) was identified as a protein that specifically associates with MLF1 by yeast two-hybrid analysis and pulldown assays, and colocalizes with MLF1 in both nuclei and cytoplasm. The protein contains two bipartite and two classical nuclear localization signals, two nuclear receptor-binding motifs (LXXLL), two leucine zippers, and multiple potential phosphorylation sites. |
Yeast two-hybrid, pulldown assay, co-localization by immunofluorescence |
Oncogene |
Medium |
15116101
|
| 2021 |
In budding yeast, Cdk1 phosphorylation of the CENPU ortholog Ame1 activates phospho-degrons that are recognized by the SCF-Cdc4 E3 ubiquitin ligase complex, targeting Ame1 for proteasomal degradation during M-phase. Binding of the Mtw1 (Mis12) complex shields the proximal phospho-degron, protecting kinetochore-bound Ame1 from degradation. This mechanism ensures efficient centromere-dependent kinetochore assembly. |
Comprehensive phosphorylation analysis of native CCAN subunits, biochemical ubiquitination assays, genetic assays in budding yeast (cdc4 mutants, overexpression toxicity) |
eLife |
High |
34308839
|
| 2019 |
CENPU promotes angiogenesis in triple-negative breast cancer by inhibiting the ubiquitination and proteasomal degradation of COX-2, leading to increased COX-2-p-ERK-HIF-1α-VEGFA signaling. CENPU knockdown reduced VEGFA production, tube formation by endothelial cells, and tumor microvessel density in xenograft models. |
shRNA knockdown, ubiquitination assay, western blot (COX-2 protein stability), endothelial tube formation assay, xenograft mouse model |
Cancer letters |
Medium |
31705927
|
| 2022 |
CENPU physically interacts with the transcription factor E2F6 and promotes its ubiquitin-mediated degradation, thereby de-repressing E2F1 transcription. E2F1 in turn binds the CENPU promoter to increase CENPU transcription, forming a positive feedback loop that accelerates G1/S transition in hepatocellular carcinoma cells. |
Co-immunoprecipitation, ubiquitination assay, chromatin immunoprecipitation (E2F1 binding to CENPU promoter), western blot, knockdown and overexpression |
International journal of biological sciences |
Medium |
35844791
|
| 2020 |
MLF1-IP (CENPU) KO mice die by embryonic day 6.5 due to degeneration of epiblasts, establishing an essential role in early embryonic development. Heterozygous KO mice are viable and fertile with no apparent immune system defects, indicating that ~50% expression is sufficient for normal postnatal development. |
Germline knockout mouse (homozygous lethal, heterozygous viable), in situ hybridization, immune phenotyping |
PloS one |
Medium |
23724000
|
| 2025 |
CENPU promotes furin activity by inhibiting lysosomal degradation of furin in triple-negative breast cancer cells. Furin, a precursor-processing enzyme, converts proNGF to NGF, which promotes breast cancer stem cell properties. Co-immunoprecipitation experiments demonstrated association between CENPU, furin, and NGF/proNGF. A furin inhibitor suppressed CENPU-promoted tumor growth in xenograft models. |
Co-immunoprecipitation, western blot (furin protein stability), ELISA (NGF), 4D-DIA quantitative proteomics, mammosphere formation, xenograft mouse model |
International journal of molecular medicine |
Low |
41041859
|
| 2025 |
CENP-U contains a single high-affinity master PLK1-docking motif that is generated by initial CDK1 priming and subsequent PLK1 phosphorylation. Biochemical and biophysical analyses showed this motif forms extensive interactions with multiple pockets on the PBD surface. Evidence did not support a requirement for PBD dimerization in CENP-U-mediated PLK1 docking. |
Biochemical binding assays, biophysical measurements, structural modelling |
bioRxivpreprint |
Medium |
bio_10.1101_2025.03.28.645803
|
| 2025 |
In budding yeast, an N-terminal auto-inhibitory segment of Dsn1 (Mis12 complex subunit) occludes binding sites for both CENP-C/Mif2 and CENP-U/Ame1 on the Mis12 complex head domain. Aurora B/Ipl1 phosphorylation of this auto-inhibitory segment would release auto-inhibition and strengthen inner–outer kinetochore connections involving CENP-U/Ame1. This was established by cryo-EM structure combined with biochemical and genetic experiments. |
Cryo-EM, biochemical binding assays, genetic assays in budding yeast |
bioRxivpreprint |
Medium |
bio_10.1101_2025.06.03.657598
|