Predictive Value of Impulse Oscillometry Combined with Fractional Expiratory Nitric Oxide Test for Asthma in Preschool Children.

Objective: Prediction of asthma in preschool children is challenging and lacks objective indicators. The aim is to observe and analyze the variances between impulse oscillometry (IOS) and fractional expiratory nitric oxide (FeNO) in preschool children with wheezing, establish a joint prediction model, and explore the diagnostic value of combining IOS with FeNO in diagnosing asthma among preschool children. Patients and methods: This study enrolled children aged 3-6 years with wheezing between June 2021 and June 2022. They were categorized as asthmatic (n=104) or non-asthmatic (n=109) after a 1-year follow-up. Clinical data, along with IOS and FeNO measurements from both groups, underwent univariate regression and multiple regression analyses to identify predictive factors and develop the most accurate model. The prediction model was built using the stepwise (stepAIC) method. The receiver operating characteristic curve (ROC), calibration curve, Hosmer-Lemeshow test, and decision curve analysis (DCA) were employed to validate and assess the model. Results: During univariate analysis, a history of allergic rhinitis, a history of eczema or atopic dermatitis, and measures including FeNO, R5, X5, R20, Fres, and R5-R20 were found to be associated with asthma diagnosis. Subsequent multivariate analysis revealed elevated FeNO, R5, and X5 as independent risk factors. The stepAIC method selected five factors (history of allergic rhinitis, history of eczema or atopic dermatitis, FeNO, R5, X5) and established a prediction model. The combined model achieved an AUROC of 0.94, with a sensitivity of 0.89 and specificity of 0.88, surpassing that of individual factors. Calibration plots and the HL test confirmed satisfactory accuracy. Conclusion: This study has developed a prediction model based on five factors, potentially aiding clinicians in early identification of asthma risk among preschool children.

Dendritic-cell-targeting virus-like particles as potent mRNA vaccine carriers.

Messenger RNA vaccines lack specificity for dendritic cells (DCs)-the most effective cells at antigen presentation. Here we report the design and performance of a DC-targeting virus-like particle pseudotyped with an engineered Sindbis-virus glycoprotein that recognizes a surface protein on DCs, and packaging mRNA encoding for the Spike protein of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) or for the glycoproteins B and D of herpes simplex virus 1. Injection of the DC-targeting SARS-CoV-2 mRNA vaccine in the footpad of mice led to substantially higher and durable antigen-specific immunoglobulin-G titres and cellular immune responses than untargeted virus-like particles and lipid-nanoparticle formulations. The vaccines also protected the mice from infection with SARS-CoV-2 or with herpes simplex virus 1. Virus-like particles with preferential uptake by DCs may facilitate the development of potent prophylactic and therapeutic vaccines.

Substrate displacement of CK1 C-termini regulates kinase specificity.

CK1 kinases participate in many signaling pathways, and their regulation is of meaningful biological consequence. CK1s autophosphorylate their C-terminal noncatalytic tails, and eliminating these tails increases substrate phosphorylation in vitro, suggesting that the autophosphorylated C-termini act as inhibitory pseudosubstrates. To test this prediction, we comprehensively identified the autophosphorylation sites on Schizosaccharomyces pombe Hhp1 and human CK1ε. Phosphoablating mutations increased Hhp1 and CK1ε activity toward substrates. Peptides corresponding to the C-termini interacted with the kinase domains only when phosphorylated, and substrates competitively inhibited binding of the autophosphorylated tails to the substrate binding grooves. Tail autophosphorylation influenced the catalytic efficiency with which CK1s targeted different substrates, and truncating the tail of CK1δ broadened its linear peptide substrate motif, indicating that tails contribute to substrate specificity as well. Considering autophosphorylation of both T220 in the catalytic domain and C-terminal sites, we propose a displacement specificity model to describe how autophosphorylation modulates substrate specificity for the CK1 family.

The Greatwall-Endosulfine-PP2A/B55 pathway controls entry into quiescence by promoting translation of Elongator-tuneable transcripts.

Quiescent cells require a continuous supply of proteins to maintain protein homeostasis. In fission yeast, entry into quiescence is triggered by nitrogen stress, leading to the inactivation of TORC1 and the activation of TORC2. Here, we report that the Greatwall-Endosulfine-PPA/B55 pathway connects the downregulation of TORC1 with the upregulation of TORC2, resulting in the activation of Elongator-dependent tRNA modifications essential for sustaining the translation programme during entry into quiescence. This process promotes U34 and A37 tRNA modifications at the anticodon stem loop, enhancing translation efficiency and fidelity of mRNAs enriched for AAA versus AAG lysine codons. Notably, some of these mRNAs encode inhibitors of TORC1, activators of TORC2, tRNA modifiers, and proteins necessary for telomeric and subtelomeric functions. Therefore, we propose a novel mechanism by which cells respond to nitrogen stress at the level of translation, involving a coordinated interplay between the tRNA epitranscriptome and biased codon usage.

Membrane binding of endocytic myosin-1s is inhibited by a class of ankyrin repeat proteins.

Myosin-1s are monomeric actin-based motors that function at membranes. Myo1 is the single myosin-1 isoform in Schizosaccharomyces pombe that works redundantly with Wsp1-Vrp1 to activate the Arp2/3 complex for endocytosis. Here, we identified Ank1 as an uncharacterized cytoplasmic Myo1 binding partner. We found that in ank1Δ cells, Myo1 dramatically redistributed from endocytic patches to decorate the entire plasma membrane and endocytosis was defective. Biochemical analysis and structural predictions suggested that the Ank1 ankyrin repeats bind the Myo1 lever arm and the Ank1 acidic tail binds the Myo1 TH1 domain to prevent TH1-dependent Myo1 membrane binding. Indeed, Ank1 overexpression precluded Myo1 membrane localization and recombinant Ank1 reduced purified Myo1 liposome binding in vitro. Based on biochemical and cell biological analyses, we propose budding yeast Ank1 and human OSTF1 are functional Ank1 orthologs and that cytoplasmic sequestration by small ankyrin repeat proteins is a conserved mechanism regulating myosin-1s in endocytosis.

Substrate displacement of CK1 C-termini regulates kinase specificity.

CK1 kinases participate in many signaling pathways; how these enzymes are regulated is therefore of significant biological consequence. CK1s autophosphorylate their C-terminal non-catalytic tails, and eliminating these modifications increases substrate phosphorylation in vitro, suggesting that the autophosphorylated C-termini act as inhibitory pseudosubstrates. To test this prediction, we comprehensively identified the autophosphorylation sites on Schizosaccharomyces pombe Hhp1 and human CK1ε. Peptides corresponding to the C-termini interacted with the kinase domains only when phosphorylated, and phosphoablating mutations increased Hhp1 and CK1ε activity towards substrates. Interestingly, substrates competitively inhibited binding of the autophosphorylated tails to the substrate binding grooves. The presence or absence of tail autophosphorylation influenced the catalytic efficiency with which CK1s targeted different substrates, indicating that tails contribute to substrate specificity. Combining this mechanism with autophosphorylation of the T220 site in the catalytic domain, we propose a displacement specificity model to describe how autophosphorylation regulates substrate specificity for the CK1 family.

AR-A014418 regulates intronic polyadenylation and transcription of PD-L1 through inhibiting CDK12 and CDK13 in tumor cells.

BACKGROUND: Immune checkpoint molecules, especially programmed death 1 (PD-1) and its ligand, programmed death ligand 1 (PD-L1), protect tumor cells from T cell-mediated killing. Immune checkpoint inhibitors, designed to restore the antitumor immunosurveillance, have exhibited significant clinical benefits for patients with certain cancer types. Nevertheless, the relatively low response rate and acquisition of resistance greatly limit their clinical applications. A deeper understanding of the regulatory mechanisms of PD-L1 protein expression and activity will help to develop more effective therapeutic strategies. METHODS: The effects of AR-A014418 and THZ531 on PD-L1 expression were detected by western blot, reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and flow cytometry. In vitro kinase assays with recombinant proteins were performed to confirm that AR-A014418 functioned as a CDK12 and CDK13 dual inhibitor. The roles of CDK12 and CDK13 in intronic polyadenylation (IPA) and transcription of PD-L1 were determined via RNA interference or protein overexpression. T-cell cytotoxicity assays were used to validate the activation of antitumor immunity by AR-A014418 and THZ531. RESULTS: AR-A014418 inhibits CDK12 to enhance the IPA, and inhibits CDK13 to repress the transcription of PD-L1. IPA generates a secreted PD-L1 isoform (PD-L1-v4). The extent of IPA was not enough to reduce full-length PD-L1 expression obviously. Only the superposition of enhancing IPA and repressing transcription (dual inhibition of CDK12 and CDK13) dramatically suppresses full-length PD-L1 induction by interferon-γ. AR-A014418 and THZ531 could potentiate T-cell cytotoxicity against tumor cells. CONCLUSIONS: Our work identifies a new regulatory pathway for PD-L1 expression and discovers CDK12 and CDK13 as promising drug targets for immune modulation and combined therapeutic strategies.

Fission yeast CK1 promotes DNA double-strand break repair through both homologous recombination and non-homologous end joining.

The CK1 family are conserved serine/threonine kinases with numerous substrates and cellular functions. The fission yeast CK1 orthologues Hhp1 and Hhp2 were first characterized as regulators of DNA repair, but the mechanism(s) by which CK1 activity promotes DNA repair had not been investigated. Here, we found that deleting Hhp1 and Hhp2 or inhibiting CK1 catalytic activities in yeast or in human cells activated the DNA damage checkpoint due to persistent double-strand breaks (DSBs). The primary pathways to repair DSBs, homologous recombination and non-homologous end joining, were both less efficient in cells lacking Hhp1 and Hhp2 activity. In order to understand how Hhp1 and Hhp2 promote DSB repair, we identified new substrates using quantitative phosphoproteomics. We confirmed that Arp8, a component of the INO80 chromatin remodeling complex, is a bona fide substrate of Hhp1 and Hhp2 that is important for DSB repair. Our data suggest that Hhp1 and Hhp2 facilitate DSB repair by phosphorylating multiple substrates, including Arp8.

Membrane binding of endocytic myosin-1s is inhibited by a class of ankyrin repeat proteins.

Myosin-1s are monomeric actin-based motors that function at membranes. Myo1 is the single myosin-1 isoform in Schizosaccharomyces pombe that works redundantly with Wsp1-Vrp1 to activate the Arp2/3 complex for endocytosis. Here, we identified Ank1 as an uncharacterized cytoplasmic Myo1 binding partner. We found that in ank1Δ cells, Myo1 dramatically redistributed from endocytic patches to decorate the entire plasma membrane and endocytosis was defective. Biochemical analysis and structural predictions suggested that the Ank1 ankyrin repeats bind the Myo1 lever arm and the Ank1 acidic tail binds the Myo1 TH1 domain to prevent TH1-dependent Myo1 membrane binding. Indeed, Ank1 over-expression precluded Myo1 membrane localization and recombinant Ank1 blocked purified Myo1 liposome binding in vitro. Based on biochemical and cell biology analyses, we propose budding yeast Ank1 and human OSTF1 are functional Ank1 orthologs and that cytoplasmic sequestration by small ankyrin repeat proteins is a conserved mechanism regulating myosin-1s in endocytosis. Summary: Fission yeast long-tailed myosin-1 binds Ank1. Ank1 ankyrin repeats associate with the Myo1 lever arm and Ank1 acidic tail binds the Myo1 TH1 domain to inhibit Myo1 membrane binding. Ank1 orthologs exists in budding yeast (Ank1) and humans (OSTF1).

Adaptive immunology of Cryptococcus neoformans infections-an update.

The fungal genus Cryptococcus comprises a group of pathogens with considerable phenotypic and genotypic diversity that can lead to cryptococcosis in both healthy and immunocompromised individuals. With the emergence of the HIV pandemic, cryptococcosis, mainly meningoencephalitis, afflicts HIV-infected patients with severe dysfunction of T cells. It has also been reported in recipients of solid organ transplantation and in patients with autoimmune diseases who take immunosuppressive agents long-term, as well as in those with unidentified immunodeficiency. The clinical outcome of the disease is primarily determined by the immune response resulting from the interplay between the host immune system and the pathogen. Most human infections are caused by Cryptococcus neoformans, and nearly all immunological studies have focused on C. neoformans. This review provides an updated understanding of the role of adaptive immunity during infection with C. neoformans in human and animal models over the past half-decade.

Multiple polarity kinases inhibit phase separation of F-BAR protein Cdc15 and antagonize cytokinetic ring assembly in fission yeast.

The F-BAR protein Cdc15 is essential for cytokinesis in Schizosaccharomyces pombe and plays a key role in attaching the cytokinetic ring (CR) to the plasma membrane (PM). Cdc15's abilities to bind to the membrane and oligomerize via its F-BAR domain are inhibited by phosphorylation of its intrinsically disordered region (IDR). Multiple cell polarity kinases regulate Cdc15 IDR phosphostate, and of these the DYRK kinase Pom1 phosphorylation sites on Cdc15 have been shown in vivo to prevent CR formation at cell tips. Here, we compared the ability of Pom1 to control Cdc15 phosphostate and cortical localization to that of other Cdc15 kinases: Kin1, Pck1, and Shk1. We identified distinct but overlapping cohorts of Cdc15 phosphorylation sites targeted by each kinase, and the number of sites correlated with each kinases' abilities to influence Cdc15 PM localization. Coarse-grained simulations predicted that cumulative IDR phosphorylation moves the IDRs of a dimer apart and toward the F-BAR tips. Further, simulations indicated that the overall negative charge of phosphorylation masks positively charged amino acids necessary for F-BAR oligomerization and membrane interaction. Finally, simulations suggested that dephosphorylated Cdc15 undergoes phase separation driven by IDR interactions. Indeed, dephosphorylated but not phosphorylated Cdc15 undergoes liquid-liquid phase separation to form droplets in vitro that recruit Cdc15 binding partners. In cells, Cdc15 phosphomutants also formed PM-bound condensates that recruit other CR components. Together, we propose that a threshold of Cdc15 phosphorylation by assorted kinases prevents Cdc15 condensation on the PM and antagonizes CR assembly.

Legumain inhibitor prevents breast cancer bone metastasis by attenuating osteoclast differentiation and function.

Breast cancer is the main lethal disease among females, and metastasis to lung and bone poses a serious threat to patients' life. Therefore, identification of novel molecular mediators that can potentially be exploited as therapeutic targets for treating osteolytic bone metastases is needed. A murine model of breast cancer bone metastasis was developed by injection of 4 T1.2 cells into the left ventricle and hence directly into the arterial system leading to bone. AEP (Asparagine endopeptidase) inhibitor combined with epirubicin or epirubicin alone was administered by intraperitoneal injection into animal model. The presence of bone metastatic and osteolytic lesions in bone were assessed by bioluminescent imaging and X-rays analysis. The expression of EMT (Epithelial-Mesenchymal Transition) relevant genes were examined by Western blotting. Cell migration and invasion were investigated with a transwell assay. Compound BIC-113, small molecule inhibitors of AEP, inhibited AEP enzymatic activity in breast cancer cell lines, and affected invasion and migration of cancer cells, but had no effect on cell growth. In animal model of breast cancer bone metastasis, compound BIC-113 combined with epirubicin inhibited breast cancer bone metastasis and attenuated breast cancer osteolytic lesions in bone by inhibiting osteoclast differentiation and EMT. These results indicate that compound BIC-113 combined with epirubicin has the potential to be used in breast cancer therapy by preventing bone metastasis via improving E-cadherin expression and inhibition of osteoclast formation.

The Influence of Alkali-Free Shotcrete Accelerators on Early Age Hydration and Property Development within Cement Systems.

Fluoride-containing alkali-free setting accelerators are a common type of admixture used in tunnel shotcrete but few studies in the literature focus on the effect of their fluoride compounds on the setting and hardening properties of accelerated cement paste under low environment temperatures. Tunnel shotcrete in cold regions or winter construction periods would be obviously influenced by low environment temperatures, especially for its fast setting and quick support applications. The objective of this work is to evaluate the early age hydration behavior of different accelerated cement pastes under 20 °C and 5 °C environment temperatures. In this study, setting time measurement, early age strength development, hydration ion leaching concentration, isothermal calorimetry, X-ray diffraction, and ESEM were performed on cement systems prepared with a non-fluoride alkali-free accelerator (aluminum sulfate solution with over 60% solid content) and a designed fluoride-containing alkali-free setting accelerator (aluminum sulfate and fluoride compound). The results showed that the fluorides obtained in alkali-free accelerators promote C3S dissolution and massive ettringite needles together with monosulfoaluminate (AFm) hydrate formation, thus leading to a quicker setting effect and low sensitivity to low environment temperatures than in non- fluoride groups. However, the rate of mechanical strength development of cement pastes hydrated within 24 h was decreased obviously when fluorine-containing alkali-free accelerator was used. This phenomenon is mainly related to the crystallization of thin-plate shape calcium fluoride (CaF2) formations and promoted conversion of ettringite to monosulfoaluminate hydrate in the accelerating period, thus weakening the denseness of C-S-H gel and inhibiting alite further hydration.

Dendrobium candidum polysaccharide reduce atopic dermatitis symptoms and modulate gut microbiota in DNFB-induced AD-like mice.

Atopic dermatitis (AD) is a chronic inflammatory skin disease with a high prevalence worldwide. Increasing evidence suggests that the gut microbiota plays an important role in the pathogenesis of AD. In this study, we sought to verify the effect of Dendrobium candidum polysaccharides (DCP) on AD induced by 2,4-Dinitrofluorobenzene (DNFB) in Balb/c mice regarding its impact on the intestinal microbiome. We found that 2-week oral administration of DCP improved AD-like symptoms and histological damage of skin, reduced mast cell infiltration, down-regulated the level of serum total IgE and the expression of pro-inflammatory cytokines such as TNF-α, IFN-γ, IL-4 and IL-6, and increased the expression level of anti-inflammatory cytokine IL-10. The beneficial effect of DCP was attributed to the restoration of the intestinal microbiome composition and the unbalance of the intestinal homeostasis. Our results indicated that DCP might be used as a promising novel microbiota-modulating agent for the treatment of AD.

Kinase domain autophosphorylation rewires the activity and substrate specificity of CK1 enzymes.

CK1s are acidophilic serine/threonine kinases with multiple critical cellular functions; their misregulation contributes to cancer, neurodegenerative diseases, and sleep phase disorders. Here, we describe an evolutionarily conserved mechanism of CK1 activity: autophosphorylation of a threonine (T220 in human CK1δ) located at the N terminus of helix αG, proximal to the substrate binding cleft. Crystal structures and molecular dynamics simulations uncovered inherent plasticity in αG that increased upon T220 autophosphorylation. The phosphorylation-induced structural changes significantly altered the conformation of the substrate binding cleft, affecting substrate specificity. In T220 phosphorylated yeast and human CK1s, activity toward many substrates was decreased, but we also identified a high-affinity substrate that was phosphorylated more rapidly, and quantitative phosphoproteomics revealed that disrupting T220 autophosphorylation rewired CK1 signaling in Schizosaccharomyces pombe. T220 is present exclusively in the CK1 family, thus its autophosphorylation may have evolved as a unique regulatory mechanism for this important family.

The anti-tumor effects of the combination of microwave hyperthermia and lobaplatin against breast cancer cells in vitro and in vivo.

BACKGROUND: Breast cancer is the main lethal disease among females. The combination of lobaplatin and microwave hyperthermia plays a crucial role in several kinds of cancer in the clinic, but its possible mechanism in breast cancer has remained indistinct. METHODS: Mouse models were used to detect breast cancer progression. Cell growth was explored with MTS (3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulphonyl)-2H-tetrazolium) and colony formation assays. Cell migration and invasion were investigated with a transwell assay. Cell apoptosis was probed with flow cytometry. The expression of apoptosis-associated proteins was examined with Western blots. RESULT: Combination treatment decreased breast cancer cell viability, colony formation, cell invasion and metastasis. In addition, the treatment-induced breast cancer cell apoptosis and autophagy, activated the c-Jun N-terminal kinase (JNK) signaling pathway, suppressed the protein kinase B (AKT)/mammalian target of rapamycin (mTOR) signaling pathway, and down-regulated IAP and Bcl-2 family protein expression. CONCLUSION: These results indicate that lobaplatin is an effective breast cancer anti-tumor agent. Microwave hyperthermia was a useful adjunctive treatment. Combination treatment was more efficient than any single therapy. The possible mechanism for this effect was mainly associated with activation of the JNK signaling pathway, inactivation of the AKT/mTOR signaling pathway and down-regulation of the Bcl-2 and IAP families.

Long non-coding RNA TUG1 promotes proliferation and migration in PDGF-BB-stimulated HASMCs by regulating miR-216a-3p/SMURF2 axis.

BACKGROUND: Abnormal proliferation and migration of human airway smooth muscle cells (HASMCs) play an important role in the development of childhood asthma. Long non-coding RNAs (lncRNAs) have been demonstrated to participate in HASMC proliferation and migration. We aimed to explore more effects and molecular mechanism of taurine upregulated gene 1 (TUG1) in childhood asthma. RESULTS: TUG1 and SMURF2 were overexpressed and miR-216a-3p was downregulated in childhood asthma patients and PDGF-BB-stimulated HASMCs. TUG1 knockdown attenuated PDGF-BB-triggered proliferation and migration of HASMCs. MiR-216a-3p was targeted by TUG1, and miR-216a-3p suppression counteracted the repressive effects of TUG1 interference on proliferation and migration in PDGF-BB-treated HASMCs. SMURF2 was a downstream target of miR-216a-3p, and SMURF2 upregulation abated the inhibiting effects of miR-216a-3p on migration and proliferation in PDGF-BB-exposed HASMCs. TUG1 sponged miR-216a-3p to positively regulate SMURF2 expression. CONCLUSION: TUG1 downregulation inhibited PDGF-BB-induced HASMC proliferation and migration by regulating miR-216a-3p/SMURF2 axis, offering novel insight into the potential application of TUG1 for childhood asthma treatment.

Localization of the ubiquitin ligase Dma1 to the fission yeast contractile ring is modulated by phosphorylation.

The timing of cytokinesis relative to other mitotic events in the fission yeast Schizosaccharomyces pombe is controlled by the septation initiation network (SIN). During a mitotic checkpoint, the SIN is inhibited by the E3 ubiquitin ligase Dma1 to prevent chromosome mis-segregation. Dma1 dynamically localizes to spindle pole bodies (SPBs) and the contractile ring (CR) during mitosis, though its role at the CR is unknown. Here, we examined whether Dma1 phosphorylation affects its localization or function. We found that preventing Dma1 phosphorylation by substituting the six phosphosites with alanines diminished its CR localization but did not affect its mitotic checkpoint function. These studies reinforce the conclusion that Dma1 localization to the SPB is key to its role in the mitotic checkpoint.

The low contagiousness and new A958D mutation of SARS-CoV-2 in children: An observational cohort study.

AIMS: To explore the contagiousness and new SARS-CoV-2 mutations in pediatric COVID-19. METHODS: This cohort study enrolled all pediatric patients admitted to 8 hospitals in Zhejiang Province of China between 21 January and 29 February 2020, their family members and close-contact classmates. Epidemiological, demographic, clinical and laboratory data were collected. Bioinformatics was used to analyze the features of SARS-CoV-2. Individuals were divided into 3 groups by the first-generation case: Groups 1 (unclear), 2 (adult), and 3 (child). The secondary attack rate (SAR) and R0 were compared among the groups. RESULTS: The infection rate among 211 individuals was 64% (135/211). The SAR in Groups 2 and 3 was 71% (73/103) and 3% (1/30), respectively; the median R0 in Groups 2 and 3 was 2 (range: 1-8) and 0 (range: 0-1), respectively. Compared with adult cases, the SAR and R0 of pediatric cases were significantly lower (p<0.05). We obtained SARS-CoV-2 sequences from the same infant's throat and fecal samples at a two-month interval and found that the new spike protein A958D mutation detected in the stool improved thermostability theoretically. CONCLUSIONS: Children have lower ability to spread SARS-CoV-2. The new A958D mutation is a potential reason for its long residence in the intestine.

Phosphorylation in the intrinsically disordered region of F-BAR protein Imp2 regulates its contractile ring recruitment.

The F-BAR protein Imp2 is an important contributor to cytokinesis in the fission yeast Schizosaccharomyces pombe. Because cell cycle-regulated phosphorylation of the central intrinsically disordered region (IDR) of the Imp2 paralog Cdc15 controls Cdc15 oligomerization state, localization and ability to bind protein partners, we investigated whether Imp2 is similarly phosphoregulated. We found that Imp2 is endogenously phosphorylated on 28 sites within its IDR, with the bulk of phosphorylation being constitutive. In vitro, the casein kinase 1 (CK1) isoforms Hhp1 and Hhp2 can phosphorylate 17 sites, and Cdk1 (also known as Cdc2) can phosphorylate the remaining 11 sites. Mutations that prevent Cdk1 phosphorylation result in precocious Imp2 recruitment to the cell division site, and mutations designed to mimic these phosphorylation events delay Imp2 accumulation at the contractile ring (CR). Mutations that eliminate CK1 phosphorylation sites allow CR sliding, and phosphomimetic substitutions at these sites reduce Imp2 protein levels and slow CR constriction. Thus, like Cdc15, the Imp2 IDR is phosphorylated at many sites by multiple kinases. In contrast to Cdc15, for which phosphorylation plays a major cell cycle regulatory role, Imp2 phosphorylation is primarily constitutive, with milder effects on localization and function. This article has an associated First Person interview with the first author of the paper.