The mechanisms by which the supramolecular order is formed inside the cell nucleus remain poorly understood. So far, two major hypotheses - ordered assembly and stochastic self-organization - have been discussed. To determine which mechanism is responsible for the formation of nuclear envelope, cells overexpressing one of the nuclear envelope proteins (lamin A, lamin B1, pom121 or ndc1) were investigated. According to the ordered assembly model, the presence of an excessive amount of a component has no effect in the formation of the normal structure of a nuclear envelope because it is programmed and cannot be distorted. In contrast, according to the self-organization concept, there is no such strictly determined cellular structures, and an excessive amount of even one component will affect the cellular organization. In the present study, formation of a redundant nuclear envelope was observed in the case of lamin B1 and lamin A overexpression. In the case of the nucleoporins pom121 and ndc1, no incorporation of the overexpressed proteins into the nuclear envelope was observed on the first day after transfection; however, the remodeling of endoplasmic reticulum elements and the formation of membrane aggregates in the cytoplasm were observed. After mitosis, pom121 from the cytoplasmic aggregates was translocated into the redundant nuclear envelope in which it induced inner nuclear membrane protrusions. Therefore, our results indicate that the formation of the nuclear envelope is not predetermined and that an excessive amount of even one protein component can affect cellular structure formation. This study concluded that nuclear envelope formation is achieved by the self-organization mechanism.
SummarySome nuclear envelope proteins are localised to both the nuclear envelope and the endoplasmic reticulum; therefore, it seems plausible that even small amounts of these proteins can influence the organisation of the endoplasmic reticulum. A simple method to study the possible effects of nuclear envelope proteins on endoplasmic reticulum organisation is to analyze nuclear envelope protein overexpression. Here, we demonstrate that Lap2β overexpression can induce the formation of cytoplasmic vesicular structures derived from endoplasmic reticulum membranes. Correlative light and electron microscopy demonstrated that these vesicular structures were composed of a series of closely apposed membranes that were frequently arranged in a circular fashion. Although stacked endoplasmic reticulum cisternae were highly ordered, Lap2β could readily diffuse into and out of these structures into the surrounding reticulum. It appears that low-affinity interactions between cytoplasmic domains of Lap2β can reorganise reticular endoplasmic reticulum into stacked cisternae. Although the effect of one protein may be insignificant at low concentrations, the cumulative effect of many non-specialised proteins may be significant.
In the modern realities of the development the transition to digital economy is impossible without the innovation component. Recognizing the importance of innovative development and, accordingly, increasing competitiveness of Russian enterprises, regions and the country as a whole determines the relevance of studying innovation management. The purpose of this work is to systematize the results of theoretical analysis of tools for the formation and development of the enterprise innovation management system. The study justifies the interaction of management functions, the main objects involved in the management of innovation, identifies relevant to these objects of business processes, the assessment of system and process approaches in terms of building a management system. The main research methods are applied methods of scientific knowledge, comparison, analysis, system, process approaches. As the main results of the study, the organizational and economic model of the innovation management system at the enterprise is formed. The developed concept of the management system reflects the necessary areas of work in the field under study, performed by subjects of different levels through the implementation of these functions, and also takes into account the impact of the external and internal environment of the enterprise on innovation. The paper determines expected results of implementing the organizational and economic model of the management system for the development of innovative activity of the enterprise.
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