Phase separation directs ubiquitination of gene-body nucleosomes.

The conserved yeast E3 ubiquitin ligase Bre1 and its partner, the E2 ubiquitin-conjugating enzyme Rad6, monoubiquitinate histone H2B across gene bodies during the transcription cycle1. Although processive ubiquitination might-in principle-arise from Bre1 and Rad6 travelling with RNA polymerase II2, the mechanism of H2B ubiquitination across genic nucleosomes remains unclear. Here we implicate liquid-liquid phase separation3 as the underlying mechanism. Biochemical reconstitution shows that Bre1 binds the scaffold protein Lge1, which possesses an intrinsically disordered region that phase-separates via multivalent interactions. The resulting condensates comprise a core of Lge1 encapsulated by an outer catalytic shell of Bre1. This layered liquid recruits Rad6 and the nucleosomal substrate, which accelerates the ubiquitination of H2B. In vivo, the condensate-forming region of Lge1 is required to ubiquitinate H2B in gene bodies beyond the +1 nucleosome. Our data suggest that layered condensates of histone-modifying enzymes generate chromatin-associated 'reaction chambers', with augmented catalytic activity along gene bodies. Equivalent processes may occur in human cells, and cause neurological disease when impaired.

Novel amino analogs of the trimethoxyphenyl ring in potent colchicine site ligands improve solubility by the masked polar group incorporation (MPGI) strategy.

The low aqueous solubility of colchicine site antimitotic agents, of which the trimethoxyphenyl (A ring) is a heavy contributor, is a serious drawback in their clinical development. We have designed new A ring analogs with chameleonic masked polar amino groups able to increase aqueous solubility and also behave as non-polar through intramolecular hydrogen bonds when bound to tubulin. We have incorporated these new A rings in several scaffolds (sulfonamides, combretastatins, phenstatins, isocombretastatins), synthesized, and assayed 43 representatives. The amino analogs show improved aqueous solubility and some of them (8, 60Z, and 67) nanomolar anti-proliferative potencies against human cancer cell lines, with the most favorable substituent being a 3-methylamino group. The antiproliferative effect relates to tubulin inhibition as shown by in vitro tubulin polymerization inhibition, immunofluorescence microscopy, and cell cycle and apoptosis analysis by flow cytometry. The compounds arrest the cell cycle of treated cells in G2/M and later develop an apoptotic response. Docking studies suggested binding at the colchicine site of tubulin with good agreement with the DFT models of the new structural variations made. The 3-methylamino-4,5­dimethoxyphenyl moiety is an example of the masked polar group incorporation (MPGI) strategy for soluble ligands binding to hydrophobic sites and a good trimethoxyphenyl ring replacement for the development of new colchicine site ligands.

Pyrite ore cargo spills as a source of soil pollution and ecological risk along the abandoned railway corridors of the Tharsis and Rio Tinto mines (Spain).

Abandoned mining railways are a prominent legacy environmental issue facing many metalliferous regions with a long mining history. However, there is a general lack of information on potentially hazardous trace elements occurring in soils alongside railroad lines as a result of hazmat cargo spills. This paper explores for the first time the effects of pyrite ore transportation on soil pollution along the old railways of Tharsis and Rio Tinto, two historical mining districts of world-class importance in the Iberian Pyrite Belt. The railroad-side topsoil was found to be extremely acidic in reaction and contains abundant pyrite, spilled on the tracks during transit, and its oxidation products (jarosite, iron oxyhydroxides, and efflorescent sulfate minerals). Compared to local background concentrations, highly elevated levels of Pb, Zn, Cu, As, Hg, Sb, Bi, Cd, Ag, and Tl were detected in both railroad lines, indicating serious anthropogenic contamination. Exposure to soil contaminants, notably Pb, As, and Tl, could pose hazards to human health and the environment. Accordingly, a specific-site risk assessment is needed before the mining railway lines are converted into recreational trails.

MicroRNAs as New Regulators of Neutrophil Extracellular Trap Formation.

Neutrophil extracellular traps (NETs) are formed after neutrophils expelled their chromatin content in order to primarily capture and eliminate pathogens. However, given their characteristics due in part to DNA and different granular proteins, NETs may induce a procoagulant response linking inflammation and thrombosis. Unraveling NET formation molecular mechanisms as well as the intracellular elements that regulate them is relevant not only for basic knowledge but also to design diagnostic and therapeutic tools that may prevent their deleterious effects observed in several inflammatory pathologies (e.g., cardiovascular and autoimmune diseases, cancer). Among the potential elements involved in NET formation, several studies have investigated the role of microRNAs (miRNAs) as important regulators of this process. miRNAs are small non-coding RNAs that have been involved in the control of almost all physiological processes in animals and plants and that are associated with the development of several pathologies. In this review, we give an overview of the actual knowledge on NETs and their implication in pathology with a special focus in cardiovascular diseases. We also give a brief overview on miRNA biology to later focus on the different miRNAs implicated in NET formation and the perspectives opened by the presented data.

Structural mechanism for the recognition and ubiquitination of a single nucleosome residue by Rad6-Bre1.

Cotranscriptional ubiquitination of histone H2B is key to gene regulation. The yeast E3 ubiquitin ligase Bre1 (human RNF20/40) pairs with the E2 ubiquitin conjugating enzyme Rad6 to monoubiquitinate H2B at Lys123. How this single lysine residue on the nucleosome core particle (NCP) is targeted by the Rad6-Bre1 machinery is unknown. Using chemical cross-linking and mass spectrometry, we identified the functional interfaces of Rad6, Bre1, and NCPs in a defined in vitro system. The Bre1 RING domain cross-links exclusively with distinct regions of histone H2B and H2A, indicating a spatial alignment of Bre1 with the NCP acidic patch. By docking onto the NCP surface in this distinct orientation, Bre1 positions the Rad6 active site directly over H2B Lys123. The Spt-Ada-Gcn5 acetyltransferase (SAGA) H2B deubiquitinase module competes with Bre1 for binding to the NCP acidic patch, indicating regulatory control. Our study reveals a mechanism that ensures site-specific NCP ubiquitination and fine-tuning of opposing enzymatic activities.

Diagnostic precision of sentinel lymph node biopsy in penile cancer.

INTRODUCTION: Sentinel lymph node biopsy (SLNB) was designed as a minimally invasive method for evaluation of nodal involvement in patients with penile cancer and nonpalpable lymph nodes. Nevertheless, SLNB is not used in a regular basis due to the lack of studies that adequately characterize the performance of this procedure. The purpose of this study was to evaluate the diagnostic performance of SLNB in patients with infiltrative penile carcinoma without palpable inguinal lymph nodes in a Colombian population. MATERIALS AND METHODS: This is a retrospective observational study of 89 patients diagnosed with infiltrative penile squamous cell carcinoma with nonpalpable inguinal lymph nodes. These patients underwent partial or complete penectomy, along with SLNB, between 2008 and 2017. Those individuals with a positive SLNB underwent inguinal lymphadenectomy, while those with a negative SLNB were followed on a quarterly basis with a physical examination and imaging to assess relapse. Statistical analysis was done using the STATA 14 software. A contingency table was made to calculate sensitivity, specificity, positive predictive value, negative predictive value, and exactitude, each one with its own confidence interval (CI) of 95%. RESULTS: There was an average follow-up of 31.4 months, and all 89 patients were evaluated; most primary tumors were T2 (55%), followed by T1 (37%), all of which were subclassified as T1b and T3 (8%). Tumours were most frequently located in the glans (43%). All patients were classified as cN0 and underwent SLNB. Sixty-one patients (69%) tested negative in the SLNB, four of whom (6%) presented with lymph node relapse. On the other hand, 28 patients (31%) tested positive in the SLNB and consequently underwent inguinal lymphadenectomy, seven of whom had negative lymph nodeinvolvement (25% false positives). According to the results, the sensitivity was 84% (95% CI, 65.3-93.6) and the specificity was 89% (95% CI, 79.4-94.7), with a false-negative rate of 6.5%. CONCLUSIONS: The SLNB using radiotracer can be a useful method for lymph node staging in patients with penile cancer and nonpalpable lymph nodes when performed in experienced centers.

Severe liver toxicity in a chronic myeloid leukemia patient probably induced by a drug interaction between imatinib and sertraline.

Our objective is to describe a chronic myeloid leukemia patient with a severe liver toxicity likely due to a drug-drug interaction between imatinib and sertraline. The patient started treatment with sertraline three months after starting imatinib. From the beginning of sertraline treatment, the patient developed vomiting, and five weeks later she developed a severe hepatic failure and was admitted to the hospital. The Naranjo nomogram showed a probable correlation between this adverse effect and the interaction between imatinib and sertraline. This interaction is extremely rare and the mechanism of action is not clear; it could be a mix of pharmacokinetic and pharmacodynamic processes. To our knowledge, this is the first case in medical literature of a severe liver toxicity due to an interaction between imatinib and sertraline. This interaction is also not described in the main secondary data sources, such as Lexicomp® and Micromedex®. However, due to the severity of this event, the hepatic function should be carefully monitored in patients treated with imatinib and sertraline.

Monoubiquitination of histone H2B is intrinsic to the Bre1 RING domain-Rad6 interaction and augmented by a second Rad6-binding site on Bre1.

Ubiquitin signaling on chromatin is linked to diverse aspects of genome regulation, including gene expression and DNA repair. The yeast RING E3 ligase Bre1 combines with the E2 Rad6 to monoubiquitinate histone H2B during transcription. Little is known about how Bre1 directs Rad6 toward transferring only a single ubiquitin to a specific lysine residue. Using a defined in vitro system, we show that the Bre1 RING domain interaction with Rad6 is minimally sufficient to monoubiquitinate nucleosomes at histone H2B Lys-123. In addition, we reveal a cluster of charged residues on the Bre1 RING domain that is critical for recognizing the nucleosome surface. Notably, a second Rad6 binding domain of Bre1 interacts with the E2 backside and potentiates ubiquitin transfer to the substrate. Taken together, our study establishes a molecular framework for how distinct RING and non-RING E3 elements cooperate to regulate E2 reactivity and substrate selection during gene expression.

Signal Transduction Reaction Monitoring Deciphers Site-Specific PI3K-mTOR/MAPK Pathway Dynamics in Oncogene-Induced Senescence.

We report a straightforward strategy to comprehensively monitor signal transduction pathway dynamics in mammalian systems. Combining targeted quantitative proteomics with highly selective phosphopeptide enrichment, we monitor, with great sensitivity, phosphorylation dynamics of the PI3K-mTOR and MAPK signaling networks. Our approach consists of a single enrichment step followed by a single targeted proteomics experiment, circumventing the need for labeling and immune purification while enabling analysis of selected phosphorylation nodes throughout signaling pathways. The need for such a comprehensive pathway analysis is illustrated by highlighting previously uncharacterized phosphorylation changes in oncogene-induced senescence, associated with diverse biological phenotypes and pharmacological intervention of the PI3K-mTOR pathway.

Protein compactness and interaction valency define the architecture of a biomolecular condensate across scales.

Non-membrane-bound biomolecular condensates have been proposed to represent an important mode of subcellular organization in diverse biological settings. However, the fundamental principles governing the spatial organization and dynamics of condensates at the atomistic level remain unclear. The Saccharomyces cerevisiae Lge1 protein is required for histone H2B ubiquitination and its N-terminal intrinsically disordered fragment (Lge11-80) undergoes robust phase separation. This study connects single- and multi-chain all-atom molecular dynamics simulations of Lge11-80 with the in vitro behavior of Lge11-80 condensates. Analysis of modeled protein-protein interactions elucidates the key determinants of Lge11-80 condensate formation and links configurational entropy, valency, and compactness of proteins inside the condensates. A newly derived analytical formalism, related to colloid fractal cluster formation, describes condensate architecture across length scales as a function of protein valency and compactness. In particular, the formalism provides an atomistically resolved model of Lge11-80 condensates on the scale of hundreds of nanometers starting from individual protein conformers captured in simulations. The simulation-derived fractal dimensions of condensates of Lge11-80 and its mutants agree with their in vitro morphologies. The presented framework enables a multiscale description of biomolecular condensates and embeds their study in a wider context of colloid self-organization.

Accuracy and prognostic impact of FDG PET/CT and biopsy in bone marrow assessment of follicular lymphoma at diagnosis: A Nation-Wide cohort study.

BACKGOUND: In the workup of follicular lymphoma (FL), bone marrow biopsy (BMB) assessment is a key component of FLIPI and FLIPI2, the most widely used outcome scores. During the previous decade, several studies explored the role of FDG-PET/CT for detecting nodal and extranodal disease, with only one large study comparing both techniques. METHODS: The aim of our study was to evaluate the diagnostic accuracy and the prognostic impact of both procedures in a retrospective cohort of 299 FL patients with both tests performed at diagnosis. In order to avoid a collinearity bias, FLIPI2 was deconstructed in its founding parameters, and the bone marrow involvement (BMI) parameter separately included as: a positive BMB, a positive PET/CT, the combined "PET/CT and BMB positive" or "PET/CT or BMB positive". These variables were also confronted independently with the POD24 in 233 patients treated with intensive regimens. RESULTS: In the total cohort, bone marrow was involved in 124 and 60 patients by BMB and PET/CT, respectively. In terms of overall survival, age > 60 y.o. and the combined "PET/CT or BMB positive" achieved statistical independence as a prognostic factor. In patients treated with an intensive regimen, only the combined "PET/CT or BMB positive" added prognostic value for a shorter overall survival, when confronted with the POD24. CONCLUSION: Our results show that in FL both BMB and PET/CT should be considered at diagnosis, as their combined assessment provides independent prognostic value in the context of the most widely use clinical scores.

Distraction by deviant sounds is modulated by the environmental context.

Evidence shows that participants performing a continuous visual categorization task respond slower following the presentation of a task-irrelevant sound deviating from an otherwise repetitive or predictable auditory context (deviant sound among standard sounds). Here, for the first time, we explored the role of the environmental context (instrumentalized as a task-irrelevant background picture) in this effect. In two experiments, participants categorized left/right arrows while ignoring irrelevant sounds and background pictures of forest and city scenes. While equiprobable across the task, sounds A and B were presented with probabilities of .882 and .118 in the forest context, respectively, and with the reversed probabilities in the city context. Hence, neither sound constituted a deviant sound at task-level, but each did within a specific context. In Experiment 1, where each environmental context (forest and city scene) consisted of a single picture each, participants were significantly slower in the visual task following the presentation of the sound that was unexpected within the current context (context-dependent distraction). Further analysis showed that the cognitive system reset its sensory predictions even for the first trial of a change in environmental context. In Experiment 2, the two contexts (forest and city) were implemented using sets of 32 pictures each, with the background picture changing on every trial. Here too, context-dependent deviance distraction was observed. However, participants took a trial to fully reset their sensory predictions upon a change in context. We conclude that irrelevant sounds are incidentally processed in association with the environmental context (even though these stimuli belong to different sensory modalities) and that sensory predictions are context-dependent.

Changes in Pain Sensitivity in Treatment for Breast Cancer: A 12-Month Follow-Up Case Series.

This study aimed to investigate changes in the pain sensory profile of women with breast cancer. Five women with unilateral breast cancer were enrolled. Participants were assessed with direct (quantitative sensory testing, QST) and indirect measures of pain sensitization (self-reported central sensitization inventory, CSI) at baseline (before surgery), 1 week after surgery, and at 1, 6, 9, and 12 months post-surgery. In the event of pain occurrence, the Leeds Assessment of Neuropathic Symptoms and Signs was also used. Nociceptive pain was the predominant pain mechanism in the postoperative period, while an increase in sensitization predominated one year after breast cancer surgery, especially in those participants who had received more treatment procedures. The participants who received more therapies for breast cancer experienced persistent pain and a higher level of sensitization. An assessment protocol including direct measurements (QST) and indirect measurement (self-reported CSI) allows for detecting changes in pain sensitivity, which can be useful for characterizing and/or predicting pain before, during, and up to one year following surgical interventions for breast cancer.

Does the Contractile Capability of Pelvic Floor Muscles Improve with Knowledge Acquisition and Verbal Instructions in Healthy Women? A Systematic Review.

Seventy percent of women with pelvic floor dysfunctions (PFDs) are estimated to present deficient consciousness of their pelvic floor muscles (PFMs) and poor ability to contract them. Improving the proprioception of PFMs, defined as the capacity to know the status and position of each body part, and adequately contracting them could be a protective factor to prevent the appearance of PFDs in the general female population. This study aimed to identify the effectiveness of educational interventions and verbal instructions on how to contract and exercise the PFMs to improve the proprioception of the PFMs in women. A systematic search of studies published in the last 20 years until March 2022 was conducted in the PubMed, Cochrane Library, Web of Science, Scopus, PEDro, Lilacs, and Dialnet databases. A meta-analysis could not be performed due to the heterogeneity in the types of studies and included populations. This review followed the PRISMA guidelines for the design, search, and reporting of studies. The methodological quality was analysed via the PEDro and the Newcastle-Ottawa scales in the case of randomised clinical trials and non-randomised studies, respectively, while the quality of evidence was determined using the SIGN grading system for evidence-based guidelines. Descriptive and experimental studies published in English, Spanish, or Portuguese that evaluated the contractile capability of the PFMs in healthy women or women without a previous diagnosis of PFD were included. Seven articles that included a total of 2507 women were found, three of which were clinical trials with PEDro scores between 5 and 9 points out of 10 and four of which were non-randomised studies with NOS scores between 6 and 8 points out of 10. The outcomes were measured through vaginal palpation, visual observation, questionnaires for PFD symptoms, and self-perception reports. This review discriminated between two types of intervention, educational programmes and verbal instructions, and evaluated the changes observed in PFM strength and knowledgeability and the symptoms of PFDs. The findings showed that educational interventions and verbal instructions improve the proprioception of PFMs in women of all ages that are healthy or without a previous diagnosis of PFDs as well as their knowledge about the pelvic floor, healthy lifestyle habits, and symptoms that are potentially indicative of PFDs. Further high-quality randomised clinical trials are warranted to draw definitive conclusions about the effectiveness of educational interventions to improve the proprioception of the PFMs in women considered healthy or with mild symptoms that may be indicative of PFDs.

Neuropsychological Study in Patients with Spinal Cord Injuries.

The present investigation was designed to determinate the nature, pattern, and extent of cognitive deficits in a group of participants with subacute and chronic spinal cord injury (SCI). METHODS: A cross-sectional study was conducted in both patients with subacute and chronic SCI. Different cognitive functions were evaluated through a neuropsychological protocol designed for this purpose, taking into account the patient's emotional state. RESULTS: A total of 100 patients suffering a spinal cord injury were evaluated. There were no differences between the two groups when age, sex, level of education, and region of origin were studied. The chronic injured patients obtained lower scores in the neuropsychological evaluation protocol respective to the subacute injured patients. CONCLUSIONS: Subjects with chronic spinal cord injury presented a cognitive profile that differed greatly in the number of altered cognitive functions as well as in their magnitude from the subacute spinal cord injured patient profile. Moreover, cognitive dysfunction may be important beyond the end of the first stage of rehabilitation as it can affect an individual's quality of life and possible integration in society.

miR-146a in Cardiovascular Diseases and Sepsis: An Additional Burden in the Inflammatory Balance?

The new concept of thrombosis associated with an inflammatory process is called thromboinflammation. Indeed, both thrombosis and inflammation interplay one with the other in a feed forward manner amplifying the whole process. This pathological reaction in response to a wide variety of sterile or non-sterile stimuli eventually causes acute organ damage. In this context, neutrophils, mainly involved in eliminating pathogens as an early barrier to infection, form neutrophil extracellular traps (NETs) that are antimicrobial structures responsible of deleterious side effects such as thrombotic complications. Although NETosis mechanisms are being unraveled, there are still many regulatory elements that have to be discovered. Micro-ribonucleic acids (miRNAs) are important modulators of gene expression implicated in human pathophysiology almost two decades ago. Among the different miRNAs implicated in inflammation, miR-146a is of special interest because: (1) it regulates among others, Toll-like receptors/nuclear factor-κB axis which is of paramount importance in inflammatory processes, (2) it regulates the formation of NETs by modifying their aging phenotype, and (3) it has expression levels that may decrease among individuals up to 50%, controlled in part by the presence of several polymorphisms. In this article, we will review the main characteristics of miR-146a biology. In addition, we will detail how miR-146a is implicated in the development of two paradigmatic diseases in which thrombosis and inflammation interact, cardiovascular diseases and sepsis, and their association with the presence of miR-146a polymorphisms and the use of miR-146a as a marker of cardiovascular diseases and sepsis.

Is deviance distraction immune to the prior sequential learning of stimuli and responses?

Past studies show that novel, task-irrelevant auditory stimuli, presented in the context of an otherwise repeated standard sound, capture participants' attention away from a focal task, resulting in behavioral distraction. While evidence has shown that making novel sounds predictable reduces or eliminates distraction, it remains unknown whether predictable target stimuli can also shield participants from novelty distraction. Using a serial reaction time task, we installed the learning of a sequence of target stimuli before testing the impact of novel sounds on performance for this sequence compared with a new one. In the learning phase, participants pressed response buttons corresponding to visual cues appearing in one of four spatial locations arranged horizontally. Unbeknownst to participants, the sequence of locations followed a pattern during several blocks before being replaced by a new pattern. The data provided solid evidence of sequence learning for the repeated sequence. In the auditory distraction phase, auditory distractors were presented immediately before each visual target. Novel sounds lengthened response times compared to the standard sound (novelty distraction), equally for learned and new sequences. We conclude that the anticipation of target stimuli and responses does not shield participants from novelty distraction and that the latter is an obligatory attentional effect.

Effect of size, seasoning and toasting level of Quercus pyrenaica Willd. wood on wine phenolic composition during maturation process with micro-oxygenation.

Seasoning and toasting treatments carried out in cooperage influence the chemical composition of the oak, and these treatments affect different oak species in different ways. For this reason, numerous studies have focused on the evaluation of both the oak wood materials and the resulting aged wines in order to optimize the different cooperage processes. Seasoning involves immobilizing the wood for long periods of time, leading to an increase in the price of the final product. When using alternative products instead of barrels, in addition to the seasoning and toasting of the wood, the size of the wood pieces is a determining factor in the characteristics of the final wine. Therefore, the objective of this work was to evaluate the polyphenolic composition of the same red wine aged with different alternative products and a small amount of oxygen for 120 days. Specifically, the effect of 2 types of seasoning and 3 types of toasting of chips and staves made from the wood of Q. pyrenaica Willd. was studied. The results showed that the size of the alternative product was the factor that determines the phenolic composition of the wines over the entire ageing process, independent of the seasoning or toasting method carried out on the wood.

Pilot Study on the Role of Circulating miRNAs for the Improvement of the Predictive Ability of the 2MACE Score in Patients with Atrial Fibrillation.

Background. Atrial fibrillation (AF) increases the risk for stroke but also for non-stroke major adverse cardiovascular events (MACE). The 2MACE score was recently proposed to predict these events. Since the interest of microRNAs (miRNAs) in cardiovascular diseases is increasing, we aimed to investigate whether miRNA levels may improve the predictive performance of the 2MACE score. Methods. We included consecutive AF patients stable on vitamin K antagonist therapy. Blood samples were drawn at baseline and plasma expression of miRNAs was assessed. During a median of 7.6 (interquartile range (IQR) 5.4-8.0) years, the occurrence of any MACE (nonfatal myocardial infarction/cardiac revascularization and cardiovascular death) was recorded. Results. We conducted a miRNA expression analysis in plasma from 19 patients with and without cardiovascular events. The miRNAs selected (miR-22-3p, miR-107, and miR-146a-5p) were later measured in 166 patients (47% male, median age 77 (IQR 70-81) years) and all were associated with a higher risk of MACE. The addition of miR-107 and miR-146a-5p to the 2MACE score significantly increased the predictive performance (c-indexes: 0.759 vs. 0.694, p = 0.004), and the model with three miRNAs also improved the predictive performance compared to the original score (c-indexes: 0.762 vs. 0.694, p = 0.012). 2MACE models with the addition of miRNAs presented higher net benefit and potential clinical usefulness. Conclusions. Higher miR-22-3p andmiR-107 and lower miR-146a-5p levels were associated with a higher risk of MACE. The addition of these miRNAs to the 2MACE score significantly increased the predictive performance for MACE, which may aid to some extent in the decision-making process about risk stratification in AF.

The COMA complex interacts with Cse4 and positions Sli15/Ipl1 at the budding yeast inner kinetochore.

Kinetochores are macromolecular protein complexes at centromeres that ensure accurate chromosome segregation by attaching chromosomes to spindle microtubules and integrating safeguard mechanisms. The inner kinetochore is assembled on CENP-A nucleosomes and has been implicated in establishing a kinetochore-associated pool of Aurora B kinase, a chromosomal passenger complex (CPC) subunit, which is essential for chromosome biorientation. By performing crosslink-guided in vitro reconstitution of budding yeast kinetochore complexes we showed that the Ame1/Okp1CENP-U/Q heterodimer, which forms the COMA complex with Ctf19/Mcm21CENP-P/O, selectively bound Cse4CENP-A nucleosomes through the Cse4 N-terminus. The Sli15/Ipl1INCENP/Aurora-B core-CPC interacted with COMA in vitro through the Ctf19 C-terminus whose deletion affected chromosome segregation fidelity in Sli15 wild-type cells. Tethering Sli15 to Ame1/Okp1 rescued synthetic lethality upon Ctf19 depletion in a Sli15 centromere-targeting deficient mutant. This study shows molecular characteristics of the point-centromere kinetochore architecture and suggests a role for the Ctf19 C-terminus in mediating CPC-binding and accurate chromosome segregation.