Three-Dimensional Bimetallic Ammonium K-Eu Nitrate with a Rare (6,6)-Connected Ion Topology Exhibiting Structural Phase Transition and Photoluminescence Properties.

A K-Eu bimetallic ammonium metal-nitrate three-dimensional (3D) framework incorporating R-N-methyl-3-hydroxyquinuclidine, (RM3HQ)2KEu(NO3)6 (RM3HQ = R-N-methyl-3-hydroxyquinuclidine, 1), was characterized and reported. Distinguishing from the former hybrid rare-earth double perovskites, 1 adopts a mixed corner- and face-sharing K+/Eu3+-centered polyhedral connectivity to form a 3D inorganic framework, showing a rare (6, 6)-connected ion topology with a 66 framework. Notably, 1 exhibits clear phase transition, and the switchable thermodynamic behavior is confirmed by variable-temperature dielectric measurements and second-harmonic generation response. Moreover, 1 also shows photoluminescence properties. The activator Eu3+ plays a crucial role in this process, leading to a significant narrow emission at 592 nm with a photoluminescence quantum yield (PLQY) of 20.76%. The fluorescence lifetime (FLT) of 1 is 4.32 ms. This finding enriches the bimetallic hybrid system for potential electronic and/or luminescence applications.

Gas-Liquid Interface Route to Hybrid Copper Bromine Perovskite Single-Crystal Membrane with Dielectric Transitions and Ferromagnetic Exchanges.

Single-crystal membranes (SCMs) show great promise in the fields of sensors, light-emitting diodes, and photodetection. However, the growth of a large-area single-crystal membranes is challenging. We report a new organic-inorganic SCMs [HCMA]2CuBr4 (HCMA = cyclohexanemethylamine) crystallized at the gas-liquid interface. It also has low-temperature ferromagnetic order, high-temperature dielectric anomalies, and narrow band gap indirect semiconductor properties. Specifically, the reversible phase transition of the compound occurs at 350/341 K on cooling/heating and exhibits dielectric anomalies and stable switching performance near the phase transition temperature. The ferromagnetic exchange interaction in the inorganic octahedra and the organic layer enables ferromagnetic ordering at low-temperature 10 K. Finally, the single crystal exhibits an indirect semiconducting property with a narrow band gap of 0.99 eV. Such rich multichannel physical properties make it a potential application in photodetection, information storage and sensors.

Halogen-Regulated Tc and X-ray Radiation Detection in 2D Hybrid Perovskite Ferroelastic Semiconductor.

Organic-inorganic hybrid perovskites (OIHPs) have received particular attention due to their characteristic structural tunability and flexibility. These features make OIHPs behave with excellent modifications on macroscopic properties, such as ferroicity or semiconductor performances, etc. Herein, we report two 2D hybrid stibium-based halide perovskite (C3H7N)3Sb2X9 (X = Br, 1; Cl, 2) ferroelastic semiconductor possessing dual switching properties of dielectric and second harmonic generation (SHG). Notably, these two hybrids exhibit halogen-regulated ferroelasticity and semiconductor properties. There is a significant difference in Curie temperature (Tc) and X-ray radiation detection sensitivity (S), i.e., the ΔTc and ΔS are 38 K and 87 µC Gyair-1 cm-2, respectively. Meanwhile, crystals 1 and 2 do not show dark current drift in cyclic measurements of different radiation doses with stable switching ratios of 30 and 10, separately. Meanwhile, these results were proven by scientific experimental results and density functional theory (DFT) calculations. Our work presents a facile and practical method to regulate macroproperties on the molecular level, providing a new vision to develop hybrid perovskite ferroic-photoelectric materials.

DYF-4 regulates patched-related/DAF-6-mediated sensory compartment formation in C. elegans.

Coordination of neurite extension with surrounding glia development is critical for neuronal function, but the underlying molecular mechanisms remain poorly understood. Through a genome-wide mutagenesis screen in C. elegans, we identified dyf-4 and daf-6 as two mutants sharing similar defects in dendrite extension. DAF-6 encodes a glia-specific patched-related membrane protein that plays vital roles in glial morphogenesis. We cloned dyf-4 and found that DYF-4 encodes a glia-secreted protein. Further investigations revealed that DYF-4 interacts with DAF-6 and functions in a same pathway as DAF-6 to regulate sensory compartment formation. Furthermore, we demonstrated that reported glial suppressors of daf-6 could also restore dendrite elongation and ciliogenesis in both dyf-4 and daf-6 mutants. Collectively, our data reveal that DYF-4 is a regulator for DAF-6 which promotes the proper formation of the glial channel and indirectly affects neurite extension and ciliogenesis.

Two oppositely-charged sf3b1 mutations cause defective development, impaired immune response, and aberrant selection of intronic branch sites in Drosophila.

SF3B1 mutations occur in many cancers, and the highly conserved His662 residue is one of the hotspot mutation sites. To address effects on splicing and development, we constructed strains carrying point mutations at the corresponding residue His698 in Drosophila using the CRISPR-Cas9 technique. Two mutations, H698D and H698R, were selected due to their frequent presence in patients and notable opposite charges. Both the sf3b1-H698D and-H698R mutant flies exhibit developmental defects, including less egg-laying, decreased hatching rates, delayed morphogenesis and shorter lifespans. Interestingly, the H698D mutant has decreased resistance to fungal infection, while the H698R mutant shows impaired climbing ability. Consistent with these phenotypes, further analysis of RNA-seq data finds altered expression of immune response genes and changed alternative splicing of muscle and neural-related genes in the two mutants, respectively. Expression of Mef2-RB, an isoform of Mef2 gene that was downregulated due to splicing changes caused by H698R, partly rescues the climbing defects of the sf3b1-H698R mutant. Lariat sequencing reveals that the two sf3b1-H698 mutations cause aberrant selection of multiple intronic branch sites, with the H698R mutant using far upstream branch sites in the changed alternative splicing events. This study provides in vivo evidence from Drosophila that elucidates how these SF3B1 hotspot mutations alter splicing and their consequences in development and in the immune system.

Loss of phosphatidylinositol-4-phosphate 5-kinase type-1 gamma (Pip5k1c) in mesenchymal stem cells leads to osteopenia by impairing bone remodeling.

Phosphatidylinositol-4-phosphate 5-kinase type-1 gamma (Pip5k1c) is a lipid kinase that plays a pivotal role in the regulation of receptor-mediated calcium signaling in multiple tissues; however, its role in the skeleton is not clear. Here, we show that while deleting Pip5k1c expression in the mesenchymal stem cells using Prx1-Cre transgenic mice does not impair the intramembranous and endochondral ossification during skeletal development, it does cause osteopenia in adult mice, but not rapidly growing young mice. We found Pip5k1c loss dramatically decreases osteoblast formation and osteoid and mineral deposition, leading to reduced bone formation. Furthermore, Pip5k1c loss inhibits osteoblastic, but promotes adipogenic, differentiation of bone marrow stromal cells. Pip5k1c deficiency also impairs cytoplasmic calcium influx and inactivates the calcium/calmodulin-dependent protein kinase, which regulates levels of transcription factor Runx2 by modulating its stability and subsequent osteoblast and bone formation. In addition, Pip5k1c loss reduces levels of the receptor activator of nuclear factor-κB ligand, but not that of osteoprotegerin, its decoy receptor, in osteoblasts in bone and in sera. Finally, we found Pip5k1c loss impairs the ability of bone marrow stromal cells to support osteoclast formation of bone marrow monocytes and reduces the osteoclast precursor population in bone marrow, resulting in reduced osteoclast formation and bone resorption. We conclude Pip5k1c deficiency causes a low-turnover osteopenia in mice, with impairment of bone formation being greater than that of bone resorption. Collectively, we uncover a novel function and mechanism of Pip5k1c in the control of bone mass and identify a potential therapeutic target for osteoporosis.

Certain heterozygous variants in the kinase domain of the serine/threonine kinase NEK8 can cause an autosomal dominant form of polycystic kidney disease.

Autosomal dominant polycystic kidney disease (ADPKD) resulting from pathogenic variants in PKD1 and PKD2 is the most common form of PKD, but other genetic causes tied to primary cilia function have been identified. Biallelic pathogenic variants in the serine/threonine kinase NEK8 cause a syndromic ciliopathy with extra-kidney manifestations. Here we identify NEK8 as a disease gene for ADPKD in 12 families. Clinical evaluation was combined with functional studies using fibroblasts and tubuloids from affected individuals. Nek8 knockout mouse kidney epithelial (IMCD3) cells transfected with wild type or variant NEK8 were further used to study ciliogenesis, ciliary trafficking, kinase function, and DNA damage responses. Twenty-one affected monoallelic individuals uniformly exhibited cystic kidney disease (mostly neonatal) without consistent extra-kidney manifestations. Recurrent de novo mutations of the NEK8 missense variant p.Arg45Trp, including mosaicism, were seen in ten families. Missense variants elsewhere within the kinase domain (p.Ile150Met and p.Lys157Gln) were also identified. Functional studies demonstrated normal localization of the NEK8 protein to the proximal cilium and no consistent cilia formation defects in patient-derived cells. NEK8-wild type protein and all variant forms of the protein expressed in Nek8 knockout IMCD3 cells were localized to cilia and supported ciliogenesis. However, Nek8 knockout IMCD3 cells expressing NEK8-p.Arg45Trp and NEK8-p.Lys157Gln showed significantly decreased polycystin-2 but normal ANKS6 localization in cilia. Moreover, p.Arg45Trp NEK8 exhibited reduced kinase activity in vitro. In patient derived tubuloids and IMCD3 cells expressing NEK8-p.Arg45Trp, DNA damage signaling was increased compared to healthy passage-matched controls. Thus, we propose a dominant-negative effect for specific heterozygous missense variants in the NEK8 kinase domain as a new cause of PKD.

Confining isolated chromophores for highly efficient blue phosphorescence.

High-efficiency blue phosphorescence emission is essential for organic optoelectronic applications. However, synthesizing heavy-atom-free organic systems having high triplet energy levels and suppressed non-radiative transitions-key requirements for efficient blue phosphorescence-has proved difficult. Here we demonstrate a simple chemical strategy for achieving high-performance blue phosphors, based on confining isolated chromophores in ionic crystals. Formation of high-density ionic bonds between the cations of ionic crystals and the carboxylic acid groups of the chromophores leads to a segregated molecular arrangement with negligible inter-chromophore interactions. We show that tunable phosphorescence from blue to deep blue with a maximum phosphorescence efficiency of 96.5% can be achieved by varying the charged chromophores and their counterions. Moreover, these phosphorescent materials enable rapid, high-throughput data encryption, fingerprint identification and afterglow display. This work will facilitate the design of high-efficiency blue organic phosphors and extend the domain of organic phosphorescence to new applications.

Implementation of Quantum Level Addressability and Geometric Phase Manipulation in Aligned Endohedral Fullerene Qudits.

Endohedral nitrogen fullerenes have been proposed as building blocks for quantum information processing due to their long spin coherence time. However, addressability of the individual electron spin levels in such a multiplet system of 4 S3/2 has never been achieved because of the molecular isotropy and transition degeneracy among the Zeeman levels. Herein, by molecular engineering, we lifted the degeneracy by zero-field splitting effects and made the multiple transitions addressable by a liquid-crystal-assisted method. The endohedral nitrogen fullerene derivatives with rigid addends of spiro structure and large aspect ratios of regioselective bis-addition improve the ordering of the spin ensemble. These samples empower endohedral-fullerene-based qudits, in which the transitions between the 4 electron spin levels were respectively addressed and coherently manipulated. The quantum geometric phase manipulation, which has long been proposed for the advantages in error tolerance and gating speed, was implemented in a pure electron spin system using molecules for the first time.

Physical optics framework for electromagnetic scattering from electrically large targets coated with a uniaxial electric anisotropic medium based on point-source excitation.

Aiming to determine the scattered estimation of complex and electrically large targets coated with the uniaxial electric anisotropic medium (UEAM) from a distributed excitation source, the demanding study is simplified by constructing the physical optics (PO) architecture which consists of three aspects, the discrete facet modeling, the tangent plane approximation, and the scattering of an infinite PEC plate coated with the UEAM based on point-source excitation, including the electric and magnetic dipole. We depict the outer surface of an electrically large scatterer as the constitution of countless tiny triangular facets. From the tangent plane approximation employed in the PO method, the scattered fields of any discretized facet induced by the equivalent electromagnetic currents (EECs) can be further evaluated as the surface fields of an infinite UEAM-coated PEC slab. Therefore, the rigorous solution of the dyadic Green's function (DGFs) for an infinite anisotropic-medium-coated PEC plate under point-source incidence is computed first. Moreover, characterizing the ray propagation process of the plane wave spectrum, the asymptotic technique of the saddle point is employed to obtain the scattered ray field in the spatial domain. Finally, the total scattered fields are obtained by the field superposition of the overall illuminated facets under point-source excitation. Compared with the reference solution, the proposed method is validated, and the simulation results of the representative shapes coated with the UEAM layer from a point source are presented.

High-throughput metabolomics discovers metabolite biomarkers and insights the protective mechanism of schisandrin B on myocardial injury rats.

Schisandrin B has been proved to possess anti-inflammatory and anti-endoplasmic effects, could improve cardiac function, inhibit apoptosis, and reduce inflammation after ischemic injury. However, the detailed metabolic mechanism and potential pathways of Schisandrin B effects on myocardial injury are unclear. Metabolomics could yield in-depth mechanistic insights and explore the potential therapeutic effect of natural products. In this study, the preparation of doxorubicin-induced myocardial injury rat model for evaluation of Schisandrin B on viral myocarditis sequelae related pathological changes and its mechanism. The metabolite profiling of myocardial injury rats was performed through ultra-high performance liquid chromatography combined with mass spectrometry combined with pattern recognition approaches and pathway analysis. A total of 15 metabolites (nine in positive ion mode and six in negative ion mode) were considered as potential biomarkers of myocardial injury, and these metabolites may correlate with the regulation of Schisandrin B treatment. A total of six metabolic pathways are closely related to Schisandrin B treatment, including glycerophospholipid metabolism, sphingolipid metabolism, purine metabolism, etc. This study revealed the potential biomarkers and metabolic network pathways of myocardial injury, and illuminated the protective mechanism of Schisandrin B on myocardial injury.

Metabolomics approach based on utra-performance liquid chromatography coupled to mass spectrometry with chemometrics methods for high-throughput analysis of metabolite biomarkers to explore the abnormal metabolic pathways associated with myocardial dysfunction.

Ultra-performance liquid chromatography/mass spectrometry-based metabolomics can been used for discovery of metabolite biomarkers to explore the metabolic pathway of diseases. Identification of metabolic pathways is key to understanding the pathogenesis and mechanism of disease. Myocardial dysfunction induced by sepsis (SMD) is a severe complication of septic shock and represents major causes of death in intensive care units; however its pathological mechanism is still not clear. In this study, ultrahigh-pressure liquid chromatography with mass spectrometry-based metabolomics with chemometrics anaylsis and multivariate pattern recognition analysis were used to detect urinary metabolic profile changes in a lipopolysaccharide-induced SMD mouse model. Multivariate statistical analysis including principal component analysis and orthogonapartial least squares discriminant analysis for the discrimination of SMD was conducted to identify potential biomarkers. A total of 19 differential metabolites were discovered by high-resolution mass spectrometry-based urinary metabolomics strategy. The altered biochemical pathways based on these metabolites showed that tyrosine metabolism, phenylalanine metabolism, ubiquinone biosynthesis and vitamin B6 metabolism were closely connected to the pathological processes of SMD. Consequently, integrated chemometric analyses of these metabolic pathways are necessary to extract information for the discovery of novel insights into the pathogenesis of disease.

Effects of Tai Chi on Cerebral Hemodynamics and Health-Related Outcomes in Older Community Adults at Risk of Ischemic Stroke: A Randomized Controlled Trial.

This study investigated the effects of Tai Chi compared with no exercise control on the cerebral hemodynamic parameters and other health-related factors in community older adults at risk of ischemic stroke. A total of 170 eligible participants were randomly allocated to Tai Chi or control group. The cerebral hemodynamic parameters and physical fitness risk factors of cardiovascular disease were measured at baseline, 12 weeks, and 24 weeks. After the 12-week intervention, Tai Chi significantly improved the minimum of blood flow velocity (BFVmin); BFVmean; pulsatility index and resistance index of the right anterior cerebral artery; and BFVmax, BFVmin, and BFVmean parameters of the right middle cerebral artery. Tai Chi training also decreased triglyceride, fasting blood glucose, and homocysteine levels, and improved balance ability. Therefore, the supervised 12-week Tai Chi exercise had potential beneficial effects on cerebral hemodynamics, plasma risk factors, and balance ability in older community adults at risk of ischemic stroke.

Simultaneously Enhancing Efficiency and Lifetime of Ultralong Organic Phosphorescence Materials by Molecular Self-Assembly.

Metal-free organic phosphorescence materials are of imperious demands in optoelectronics and bioelectronics. However, it is still a formidable challenge to develop a material with simultaneous efficiency and lifetime enhancement under ambient conditions. In this study, we design and synthesize a new class of high efficient ultralong organic phosphorescence (UOP) materials through self-assembly of melamine and aromatic acids in aqueous media. A supramolecular framework can be formed via multiple intermolecular interactions, building a rigid environment to lock the molecules firmly in a three-dimensional network, which not only effectively limits the nonradiative decay of the triplet excitons but also promotes the intersystem crossing. Thus, the supermolecules we designed synchronously achieve an ultralong emission lifetime of up to 1.91 s and a high phosphorescence quantum efficiency of 24.3% under ambient conditions. To the best of our knowledge, this is the best performance of UOP materials with simultaneous efficiency and lifetime enhancement. Furthermore, it is successfully applied in a barcode identification in darkness. This result not only paves the way toward high efficient UOP materials but also expands their applications.

Combined Phycocyanin and Hematoporphyrin Monomethyl Ether for Breast Cancer Treatment via Photosensitizers Modified Fe3O4 Nanoparticles Inhibiting the Proliferation and Migration of MCF-7 Cells.

Photodynamic therapy (PDT), combining the laser and photosensitizers to kill tumor cells, has the potential to address many current medical requirements. In this study, magnetic Fe3O4 nanoparticles were first employed as cores and modified with oleic acid (OA) and 3-triethoxysilyl-1-propanamine. Then, the photosensitizers phycocyanin (PC) and hematoporphyrin monomethyl ether (HMME), which might be able to stimulate the cell release of reactive oxygen species after the irradiation of a near-infrared (NIR) laser, were grafted on the surface of such nanoparticles. Our results revealed the high-efficiency inhibition of breast cancer MCF-7 cells growing upon near-infrared irradiation both in vitro and in vivo. Furthermore, it was the synergy between the natural photosensitizers PC and the synthetic photosensitizers HMME that deeply influenced such inhibition compared to the groups that used either of these medicines alone. To utilize the combination of different photosensitive agents, our study thus provides a new strategy for breast cancer treatment.

Hydrogen-Bonded Organic Aromatic Frameworks for Ultralong Phosphorescence by Intralayer π-π Interactions.

Ultralong organic phosphorescence (UOP) based on metal-free porous materials is rarely reported owing to rapid nonradiative transition under ambient conditions. In this study, hydrogen-bonded organic aromatic frameworks (HOAFs) with different pore sizes were constructed through strong intralayer π-π interactions to enable ultralong phosphorescence in metal-free porous materials under ambient conditions for the first time. Impressively, yellow UOP with a lifetime of 79.8 ms observed for PhTCz-1 lasted for several seconds upon ceasing the excitation. For PhTCz-2 and PhTCz-3, on account of oxygen-dependent phosphorescence quenching, UOP could only be visualized in N2 , thus demonstrating the potential of phosphorescent porous materials for oxygen sensing. This result not only outlines a principle for the design of new HOFs with high thermal stability, but also expands the scope of metal-free luminescent materials with the property of UOP.

Dynamic Ultralong Organic Phosphorescence by Photoactivation.

Smart materials with ultralong phosphorescence are rarely investigated and reported. Herein we report on a series of molecules with unique dynamic ultralong organic phosphorescence (UOP) features, enabled by manipulating intermolecular interactions through UV light irradiation. Our experimental data reveal that prolonged irradiation of single-component organic phosphors of PCzT, BCzT, and FCzT under ambient conditions can activate UOP with emission lifetimes spanning from 1.8 to 1330 ms. These phosphors can also be deactivated back to their original states with short-lived phosphorescence by UV irradiation for 3 h at room temperature or through thermal treatment. Additionally, the dynamic UOP was applied successfully for a visual anti-counterfeiting application. These findings may provide unique insight into dynamic molecular motion for optical processing and expand the scope of smart-response materials for broader applications.

Subjective perceived impact of Tai Chi training on physical and mental health among community older adults at risk for ischemic stroke: a qualitative study.

BACKGROUND: Evidence from quantitative studies suggest that Tai Chi produces a variety of health-related benefits, but few qualitative studies have investigated how older adults perceive the benefit of Tai Chi. The objective of the current study was to qualitatively evaluate the perceived benefits of Tai Chi practice among community older population. METHODS: This study was conducted with participants from a trial examining the effects of a 12-week Tai Chi training on ischemic stroke risk in community older adults (n = 170). A total of 20 participants were randomly selected from a convenience sample of participants who had completed 12-week Tai Chi training (n = 68) were interviewed regarding their perceived benefit on physical and mental health and whether Tai Chi exercise was suitable for the elderly. RESULTS: All participants agreed that Tai Chi training could relax their body and make them comfortable. Most of them thought Tai Chi training could promote physical health, including relieving pain, enhancing digestion, strengthening immunity, enhancing energy and improving sleep quality, enhancing their mental and emotional state (e.g. improving mood and reducing anxiety, improving concentration and promoting interpersonal relationship). Most of participants also agreed that Tai Chi exercise was appropriate for community older people. Three primary themes emerged from content analysis: Improving physical health; Enhancing mental and emotional state; Conforming with the request of the elderly. CONCLUSION: The findings indicate that regular Tai Chi exercise may have positive benefits in terms of improved physical health and mental state among community elderly population, and may be useful and feasible body-mind exercise to community elderly population for its positive effects and advantages. TRIAL REGISTRATION: ChiCTR ChiCTR-TRC-13003601 . Registered 23 July 2014.

[Effects of tetramethylpyrazine on trigeminal neuralgia induced by chronic constriction injury of infraorbital nerve in rats].

Trigeminal neuralgia (TN) is a kind of recurrent transient and severe pain that is limited to the trigeminal nerve in one or more branches. The clinical incidence of TN is high, which seriously affects the quality of life of the patients and is difficult to cure. The present study investigated the effects of tetramethylpyrazine (TMP) on TN induced by chronic constriction injury of the infraorbital nerve (ION-CCI) in rats. Adult male Sprague-Dawley rats were randomly assigned to four groups: sham, sham treated with TMP (Sham+TMP), TN model (TN), and TN treated with TMP (TN+TMP). The rat TN model was established by ION-CCI and TMP (50 mg/kg) was injected intraperitoneally once a day for 2 weeks after operation. The mechanical response threshold was tested by the electronic von Frey filaments. The expression of CGRP in the trigeminal ganglia (TGs) of rats on the operative side was detected by RT-PCR, immunohistochemical staining and Western blot. In 15 days after operation, TN group showed a robust decrease in mechanical response threshold as compared with sham group. From day 9 to day 15 after operation, TMP treatment significantly suppressed the TN-induced mechanical hyperalgesia (P < 0.05). On day 15 after operation, RT-PCR, immunohistochemical staining and Western blot analysis showed an obvious increase in expression level of CGRP in TGs of TN group compared with sham group, which was downregulated by TMP treatment (P < 0.05). These results suggested that TMP might have a therapeutic potential for the treatment of TN through regulating CGRP expression in the TGs.

PIPKIγ targets to the centrosome and restrains centriole duplication.

Centriole biogenesis depends on the polo-like kinase (PLK4) and a small group of structural proteins. The spatiotemporal regulation of these proteins at pre-existing centrioles is essential to ensure that centriole duplication occurs once per cell cycle. Here, we report that phosphatidylinositol 4-phosphate 5-kinase type-1 gamma (PIP5K1C, hereafter referred to as PIPKIγ) plays an important role in centriole fidelity. PIPKIγ localized in a ring-like pattern in the intermediate pericentriolar materials around the proximal end of the centriole in G1, S and G2 phases, but not in M phase. This localization was dependent upon an association with centrosomal protein of 152 KDa (CEP152). Without detaining cells in S or M phase, the depletion of PIPKIγ led to centriole amplification in a manner that was dependent upon PLK4 and spindle assembly abnormal protein 6 homolog (SAS6). The expression of exogenous PIPKIγ reduced centriole amplification that occurred as a result of endogenous PIPKIγ depletion, hydroxyurea treatment or PLK4 overexpression, suggesting that PIPKIγ is likely to function at the PLK4 level to restrain centriole duplication. Importantly, we found that PIPKIγ bound to the cryptic polo-box domain of PLK4 and that this binding reduced the kinase activity of PLK4. Together, our findings suggest that PIPKIγ is a novel negative regulator of centriole duplication, which acts by modulating the homeostasis of PLK4 activity.