Cryo-EM structure of the human NKCC1 transporter reveals mechanisms of ion coupling and specificity

The sodium-potassium-chloride transporter NKCC1 (SLC12A2) performs Na+-dependent Cl- and K+ ion uptake across plasma membranes. NKCC1 is important for regulating e.g. cell volume, hearing, blood pressure, and chloride gradients defining GABAergic and glycinergic signaling in brain. Here, we present a 2.6 Å resolution cryo-electron microscopy (cryo-EM) structure of human NKCC1 in the substrate-loaded (Na+, K+, 2 Cl-) and inward-facing conformation adopting an occluded state that has also been observed for the SLC6 type transporters MhsT and LeuT. Cl- binding at the Cl1 site together with the nearby K+ ion provide a crucial bridge between the LeuT-fold scaffold and bundle domains. Cl- ion binding at the Cl2 site seems to undertake a structural role similar to a conserved glutamate of SLC6 transporters and may allow for chloride-sensitive regulation of transport. Supported by functional studies in mammalian cells and computational simulations we describe the Na+ binding site and a putative Na+ release pathway along transmembrane helix 5. The results provide insight into the structure-function relationship of NKCC1 with broader implications for other SLC12 family members.

PROBLEMS OF THE LEGAL REGIME OF TRANSPORT LANDS IN THE RUSSIAN FEDERATION

The article examines the problems of the legal regime of land transport. Transport is the most important component of the production and social sphere, in connection with which the problems of legal regulation of transport lands are urgent. The authors refer to the problems of the legal regime of transport lands: the problem of imbalance in the development of a unified transport system of the Russian Federation; the problem of legal uncertainty in the practice of applying legislation in the field of legal regulation of lands of various types of transport; the legal problem of land use of transport lands in the process of formation of Russian urban settlements. According to the authors, in order to resolve legal conflicts, it is necessary to correlate the norms of transport legislation with the norms and documents of territorial planning, which are established by state authorities and local self-government bodies, which are local by-laws. This condition is necessary, among other things, to ensure the safety of transport infrastructure facilities.

Structure and lipid-mediated remodelling mechanism of the Na+/H+ exchanger NHA2

Na+/H+ exchangers catalyse an ion-exchange activity that is carried out in most, if not all cells. SLC9B2, also known as NHA2, correlates with the long-sought after sodium/lithium (Na+/Li+) exchanger linked to the pathogenesis of diabetes mellitus and essential hypertension in humans. Despite its functional importance, structural information and the molecular basis of its ion-exchange mechanism have been lacking. Here, we report the cryo EM structures of bison NHA2 in detergent and in nanodiscs at 3.0 and 3.5 Å resolution, respectively. NHA2 shares closest structural similarity to the bacterial electrogenic Na+/H+ antiporter NapA, rather than other mammalian SLC9A members. Nevertheless, SSM-based electrophysiology results with NHA2 show the catalysis of electroneutral rather than electrogenic ion exchange, and the ion binding site is quite distinctive, with a tryptophan arginine-glutamate triad separated from the well established ion-binding aspartates. These triad residues fine-tune ion binding specificity, as demonstrated by a salt-bridge swap mutant that converts NHA2 into a Li+ specific transporter. Strikingly, an additional N terminal helix in NHA2 establishes a unique homodimer with a large ~ 25 Å intracellular gap between protomers. In the presence of phosphatidylinositol lipids, the N-terminal helix rearranges and closes this gap. We confirm that dimerization of NHA2 is required for activity in vivo, and propose that the N- terminal helix has evolved as a lipid-mediated remodelling switch for regulation of transport activity.

The Eurasian Economic Union: on the «Strategy-2025» and on the transport and logistics component of the document`s issues

The article briefly describes the content of the new conceptual and programmatic perspective document of the Eurasian Economic Union (EAEU) –«Strategic directions for the development of the Eurasian economic integration until 2025» («Strategy-2025»). The transport and logistics component of the document`s problems is commented on in more detail. In the course of these comments, proposals are substantiated to modify the legal framework of the EAEU in the aspect of strengthening the institutional regulation of transport integration of the participating countries on the basis of expanding the functional powers of regulators (subjects of the unified interstate regulatory system), including the Eurasian Economic Commission (EAEC) and its departments.

Detailed imaging of mitochondrial transport and precise manipulation of mitochondrial function with genetically-encoded photosensitizers in adult Drosophila neurons

Precise distribution of mitochondria is essential for maintaining neuronal homeostasis. Although detailed mechanisms governing the transport of mitochondria have emerged, it is still poorly understood how the regulation of transport is coordinated in space and time within the physiological context of an organism. How alteration in mitochondrial functionality may trigger changes in organellar dynamics also remains unclear in this context. Therefore, the use of genetically-encoded tools to perturb mitochondrial functionality in real time would be desirable. Here we describe methods to interfere with mitochondrial function with high spatiotemporal precision with the use of photosensitisers in vivo in the intact wing nerve of adult Drosophila. We also provide details on how to visualise the transport of mitochondria and to improve the quality of the imaging to attain super-resolution in this tissue.

Features of labor regulation of transport workers in the context of COVID-19 pandemic

The article deals with the issue of legal regulation of labor relations in transport in emergency situations. The author analyzes the current labor legislation that regulates the specifics of regulating the labor of employees of transport organizations; the possibility of concluding and terminating labor contracts in emergency situations, and the specifics of their responsibility. Special attention is given to the specifics of the operation of transport enterprises during the COVID-19 pandemic and in other threatening situations in order to ensure the transport security of Russia. The author notes the actual tasks of transport enterprises in special conditions, justifies the need for special requirements for transport workers, the importance of pre-trip medical examinations.

NATIONAL INNOVATIVE TRANSPORT HUB AS A SYSTEM OF STATE REGULATION OF INNOVATIVE DEVELOPMENT OF TRANSPORT INFRASTRUCTURE

Introduction. The transport industry and its supporting component – transport infrastructure are extremely important for ensuring the innovative development of the country. This is due to the fact that the operation of transport infrastructure, transport networks and vehicles covers almost all types of innovations: product, procedural, marketing, management.The hypothesis of scientific research is finding out that the results of the transport industry obtained in the course of innovation activities extend to other sectors of the economy (there is a so-called diffusion of innovations).The aim is substantiation of the architecture of the national innovative transport HUB as a system of state regulation of innovative development of transport infrastructure.The research methodology is comparative analysis and graphical method – to reflect trends in transport infrastructure; systematization and classification – for the classification of structural elements of transport infrastructure; system approach – for the formation of theoretical foundations of state regulation of transport infrastructure in the system of economic knowledge; modeling – to substantiate the model of innovative development of transport infrastructure.Results: the main factors determining the conditions and nature of forced internal migration in Ukraine in 2014–2017 were determined. The main directions of forced internal migration since the beginning of hostilities in the Donbass were determined. The emergence of regional asymmetry of migration processes at the level of aggregate migratory flows is investigated developed a model of innovative development of transport infrastructure in the form of national innovative transport HUB as a system of state regulation of the hexagon of individual components: innovation-production, resource-energy, environmental, investment, international and social, the use of which will create integrated into the world transport network safe, interactive, innovative and efficient transport infrastructure of Ukraine, increase the level of competitiveness of the national economy. Conclusions: the concept of innovative development of transport infrastructure is specified; a systematic analysis and classified models of state regulation of transport infrastructure, proposed a theoretical and methodological approach to the formation of national innovative transport HUB as a system of state regulation of innovative development of transport infrastructure, the implementation of which will bring the level of their provision and infrastructure to European standards. environment, to ensure socially responsible innovative development of transport infrastructure.

Regarding certain historical and legal preconditions for the formation and development of transport law

The article examines some historical and legal prerequisites for the formation and development of transport law as a complexbranch of law. It is emphasized that the regulation of transport activities in the ancient and medieval world was carried out mainlythrough trade and maritime customs, and points to the application of legal customs in transport law today.Transport law is a complex branch of law, and depending on the prevailing legal relationship, it can be considered as part of civil,commercial or administrative law. There was no separate school of transport law in the former USSR and Ukraine. Today, research onthe problems of transport law and the development of proposals to overcome them are carried out by scientists belonging to the scientificschools of commercial, civil and administrative law. Within these schools, there are separate groups of scientists or research departmentsthat carry out research to improve transport legislation.In transport law, the regulation of shipping and maritime trade developed first of all. It was there that the first legal customsappeared. Among the legal customs used in transport law, port customs (customs of the port) stand out.In Russia, trade was conducted mainly by river and sea “from the Vikings to the Greeks”, which ran from the Scandinavian Peninsula,the Baltic Sea, the Dnieper and the Black Sea to Byzantium. Thanks to this trade route, the inhabitants of Kievan Rus built boatsand developed a transport system. In addition to sea and river routes, the territory of modern Ukraine was a land route from Asia toEurope, stretching from southeast to northwest of our country – the legendary “Aryan route”, which according to some historians thousandsof years ago from the Indian subcontinent to Western and Northern Europe came the Aryan tribe, which gave development to theEuropean peoples. The possibility of applying port customs is provided by Art. 78 of the Code of Merchant Shipping of Ukraine. In addition to ports,the customs of merchant shipping are widely used. For example, in accordance with Art. 6 (concerning the permission to include in theagreements provided by the Code of Merchant Shipping of Ukraine, conditions on application of foreign legislation and customs ofmerchant shipping in case the parties may deviate from its rules in accordance with the current Code); art. 71 (in emergency cases, whenthe vessel has to be on the high seas for a long time and the body of the deceased cannot be saved, the captain of the vessel has the rightto give the body to the sea according to maritime customs, about which the corresponding act is made and the corresponding record ismade; Art. 146 (cargo is placed on the ship at the discretion of the captain, but can not be placed on deck without the written consentof the sender, except for cargo, the carriage of which on deck is allowed in accordance with applicable rules and customs); art. 293(concerning the possibility of determining the type of accident, calculating the size of the general accident and compiling the dispatchby the dispatcher in conditions of incompleteness of the law) of the Merchant Shipping Code of Ukraine of May 23, 1995.