CIN85 drives B cell responses by linking BCR signals to the canonical NF-κB pathway

CIN85 transduces B cell receptor signals to IKK-β, and its expression in B cells is essential for T cell–independent type II antibody responses in mice

Characterization of low-lying excited states of proteins by high-pressure NMR

Hydrostatic pressure alters the free energy of proteins by a few kJ mol-1, with the amount depending on their partial molar volumes. Because the folded ground state of a protein contains cavities, it is always a state of large partial molar volume. Therefore pressure always destabilises the ground state and increases the population of partially and completely unfolded states. This is a mild and reversible conformational change, which allows the study of excited states under thermodynamic equilibrium conditions. Many of the excited states studied in this way are functionally relevant; they also seem to be very similar to kinetic folding intermediates, thus suggesting that evolution has made use of the 'natural' dynamic energy landscape of the protein fold and sculpted it to optimise function. This includes features such as ligand binding, structural change during the catalytic cycle, and dynamic allostery

VYSOCHANSK (KHARKOV REGION) SCHOOL #2 GEOMODEL

The model was created in the О. М. Beketov National University of Urban Economy in Kharkiv students and teachers project "3D Models in Google Earth

NMR Studies of SH3 Domain Structure and Function

SH3 domains are excellent models for probing folding and protein interactions. This thesis describes NMR studies of several SH3 domains, including the N-terminal SH3 domain of the Drosophila adaptor protein Drk (drkN SH3 domain), the SH3 domain of the proto-oncogene tyrosine-kinase Fyn, and the SH3 domains of the human adaptor protein CIN85, involved in Cbl-mediated downregulation of epidermal growth factor receptor (EGFR) and other receptor tyrosine kinases (RTKs). The drkN SH3 domain is an ideal system for studying disordered states. The unique quality of this isolated domain is that it exists in an approximately 50/50 equilibrium between its folded and unfolded states under non-denaturating buffer conditions. Interestingly, the single T22G mutation dramatically stabilizes the domain. Here the NMR structures of the drkN SH3 domain and its T22G mutant are determined and compared in order to illuminate the causes of the marginal stability of the domain. Solvent exposure of the folded and the unfolded drkN SH3 domains are probed and compared with a novel NMR technique using molecular oxygen dissolved in solution as a paramagnetic probe. The changes in partial molar volume along the folding trajectories of the drkN SH3 and Fyn SH3 domains are also studied and analyzed here in terms of changes in protein hydration and packing accompanying folding. Finally, the interactions between the SH3 domains of CIN85 and ubiquitin are discussed. All three are shown to bind ubiquitin. The structure of the SH3-C domain in complex with ubiquitin is presented and the effect of disruption of ubiquitin binding on ubiquitination of CIN85 and EGFR in vivo is discussed. SH3 domains are easily amendable to a wide range of NMR approaches and provide a good system for development and testing of novel methods. Through the use of these approaches significant insights into details of SH3 domain structure, stability, mechanisms of folding and cellular function have been gained.Ph

Організація діалогової взаємодії дорослих і дітей в розвивальному середовищі груп раннього віку

The article considers the problem of organizing dialogic interaction of adults and children in the developmental environment of early age groups. The article presents the results of theoretical research on the concepts of "dialogue", "interaction", "dialogue interaction". It is determined, that in most scientific sources dialogue is considered as a form, method and means of social contacts, which is realized by the individual in the subject-subject interaction. Educational influences, focused on dialogic interaction, able to stimulate speech and interpersonal interaction between children, are just beginning to develop and do not have wide practical application. Based on the following ideas about dialogue, the development of dialogical interaction of adults and young children in the educational space of ZDO, it is necessary to focus on solving the following tasks: establishing emotional contact between participants in educational interaction; mastering verbal and nonverbal means of communication; ability to perform actions together with other participants in the educational process. The main models of dialogic interaction, their uniqueness and effectiveness are described, namely: interaction that encourages the child to active cognition (cognitive development occurs during interaction with objects, mastering texts, actions in a specially created space, and the core of such a system is active action ), reorientation of the child's behavior in interaction with an adult (involves natural and logical changes in unwanted behavior of the child, which strengthens the child's sense of self-worth and shapes his/her character; the following types: sandwich, steps, triplets, pattern), supportive interaction task: to help the child to form a positive image of themselves, to realize their value and uniqueness; the following types: emotional, resource, co-existence support). The importance of maintaining consistency in the organization of interaction is emphasized: from the usual way in the usual conditions to the new way in the new unusual space. The algorithm of the organization of dialogue interaction is defined: I look, what the child does now; I feel and analyze what he/she needs now, what he/she expects from me; I give him/her what he/she needs. Emphasis is placed on the importance of compliance with speech strains when interacting with children early, compliance with the rules of communication by all participants in the educational process. Possibilities of application of the offered models of dialogue interaction in modern conditions of reforming of education in Ukraine are definedРозглянуто проблему організації діалогічної взаємодії дорослих і дітей у розвивальному середовищі груп раннього віку. Представлено результати теоретичного дослідження понять «діалог», «взаємодія», «діалогічна взаємодія». Визначено, що в більшості наукових джерел діалог розглядається як форма, метод і засіб соціальних контактів, які реалізуються особистістю у суб’єкт-суб’єктній взаємодії. Виховні впливи, орієнтовані на діалогічну взаємодію, здатні стимулювати мовленнєву та міжособистісну взаємодію дітей, тільки починають розвиватися і не мають широкого практичного застосування. Виходячи з таких уявлень про діалог, розвиток діалогічної взаємодії дорослих і дітей раннього віку в освітньому просторі ЗДО необхідно зосередити увагу на розв’язанні таких завдань: встановлення емоційного контакту між учасниками освітньої взаємодії; оволодіння вербальними та невербальними засобами спілкування; вміння виконувати дії разом з іншими учасниками освітнього процесу. Охарактеризовано основні моделі діалогічної взаємодії, їх унікальність та ефективність, а саме: взаємодія, що спонукає дитину до активного пізнання (пізнавальний розвиток відбувається під час взаємодії з об’єктами, засвоєння текстів, дій у спеціально створеному просторі, а стрижнем такої системи є активна дія самої дитини), переорієнтація поведінки дитини у взаємодії з дорослим (сприяє природним та логічним змінам небажаної поведінки дитини, що посилює почуття власної гідності дитини та формує її характер; такі види: сендвіч, кроки, трійчатка, зразок), завдання підтримуючої взаємодії: допомогти дитині сформувати позитивний образ себе, усвідомити свою цінність та неповторність; такі види: емоційна, ресурсна, со-буттєва (ситуаційна) підтримка). Підкреслюється важливість збереження послідовності в організації взаємодії: від звичного способу в звичних умовах до нового способу в новому незвичайному просторі. Визначено алгоритм організації діалогової взаємодії: дивлюся, що зараз робить дитина; відчуваю і аналізую, що їй зараз потрібно, чого вона очікує від мене; даю їй те, що їй потрібно. Акцентовано увагу на важливості дотримання мовленнєвих формул при спілкуванні з дітьми раннього віку, дотримання правил спілкування всіма учасниками освітнього процесу. Визначено можливості застосування запропонованих моделей діалогової взаємодії в сучасних умовах реформування освіти в Україн

NMR Structure of the Human Rad18 Zinc Finger in Complex with Ubiquitin Defines a Class of UBZ Domains in Proteins Linked to the DNA Damage Response

Ubiquitin-mediated interactions are critical for the cellular DNA damage response (DDR). Therefore, many DDR-related proteins contain ubiquitin-binding domains, including ubiquitin-binding zinc fingers (UBZs). The majority of these UBZ domains belong to the C₂H₂ (type 3 Polη-like) or C₂HC (type 4 Rad18-like) family. We have used nuclear magnetic resonance (NMR) spectroscopy to characterize the binding to ubiquitin and determine the structure of the type 4 UBZ domain (UBZ4) from human Rad18, which is a key ubiquitin ligase in the DNA damage tolerance pathway responsible for monoubiquitination of the DNA sliding clamp PCNA. The Rad18-UBZ domain binds ubiquitin with micromolar affinity and adopts a β1−β2−α fold similar to the previously characterized type 3 UBZ domain (UBZ3) from the translesion synthesis DNA polymerase Polη. However, despite nearly identical structures, a disparity in the location of binding-induced NMR chemical shift perturbations shows that the Rad18-UBZ4 and Polη-UBZ3 domains bind ubiquitin in distinctly different modes. The Rad18-UBZ4 domain interacts with ubiquitin with the α-helix and strand β1 as shown by the structure of the Rad18-UBZ domain–ubiquitin complex determined in this work, while the Polη-UBZ3 domain exclusively utilizes the α-helix. Our findings suggest the existence of two classes of UBZ domains in DDR-related proteins with similar structures but unique ubiquitin binding properties and provide context for further study to establish the differential roles of these domains in the complex cellular response to DNA damage

Peptide Uptake Is Essential for Borrelia burgdorferi Viability and Involves Structural and Regulatory Complexity of its Oligopeptide Transporter

Borrelia burgdorferi is an extreme amino acid (AA) auxotroph whose genome encodes few free AA transporters and an elaborate oligopeptide transport system (B. burgdorferi Opp [BbOpp]). BbOpp consists of five oligopeptide-binding proteins (OBPs), two heterodimeric permeases, and a heterodimeric nucleotide-binding domain (NBD). Homology modeling based on the crystal structure of liganded BbOppA4 revealed that each OBP likely binds a distinct range of peptides. Transcriptional analyses demonstrated that the OBPs are differentially and independently regulated whereas the permeases and NBDs are constitutively expressed. A conditional NBD mutant failed to divide in the absence of inducer and replicated in an IPTG (isopropyl-β-d-thiogalactopyranoside) concentration-dependent manner. NBD mutants grown without IPTG exhibited an elongated morphotype lacking division septa, often with flattening at the cell center due to the absence of flagellar filaments. Following cultivation in dialysis membrane chambers, NBD mutants recovered from rats not receiving IPTG also displayed an elongated morphotype. The NBD mutant was avirulent by needle inoculation, but infectivity was partially restored by oral administration of IPTG to infected mice. We conclude that peptides are a major source of AAs for B. burgdorferi both in vitro and in vivo and that peptide uptake is essential for regulation of morphogenesis, cell division, and virulence