Proteasome Dynamics: Will the Territory of Proteasomes Be Claimed By Mitochondrial Proteases Under Stress Conditions?

Enenkel, Cordula

doi:10.21767/2471-8084.100036

Cited by 3 publications

(4 citation statements)

References 26 publications

(27 reference statements)

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“…We demonstrated translocation of PFs from the nucleus to cytoplasm via nuclear pores (Figure 1c). Previously it was hypothesized that PRs were transferred to cytoplasm in a same way [9]. Therefore, we were the first to directly demonstrate that the intranuclear/intracytoplasmic aggregates named HERDS are composed of three morphologically distinct types of particles, IGs, PRs, and PFs.…”

Section: Figurementioning

confidence: 87%

Ultrastructural Study and X-Ray Microanalysis of Apoptotic Lymphoma Cells U-937

Snigirevskaya¹,

Moshkov²,

Komissarchik³

2017

Biochem Mol biol J

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DescriptionWe studied the ultrastructure and ionic cell contents of human histiocytic lymphoma U-937 cells induced for apoptosis by two external agents, hypertonic shock and etoposide. Despite different mechanisms of action, the deterioration of cellular functions triggered by these agents followed similar patterns. The most dramatic changes-condensation of the chromatin and formation of "crescent-shaped nuclei", nucleus fragmentation, disappearance of nucleoli, and appearance of aggregated particles in the interchromatin nuclear space were observed in the nucleus. The aggregated particles observed in the interchromatin nuclear space, were lacking limiting membrane and presumably derived from the aggregates of interchromatin granules (IGs), so called speckles. The speckles, were shown previously to be highly dynamic nuclear structures associated with: m-RNA-splicing, transcription, and processing of pre-mRNA [1]. We attribute the described here aggregates to the "HERDS" (heterogeneous ectopic RNP-derived structures) type described by Biggiogera and co-authors [2,3].In contrast to other cytoplasmic aggregates such as aggresomes, processing bodies (Pbs) or stress bodies (SBs) HERDS were observed both in the nucleus, and in cytoplasm [4,5]. They emerge in response to impairment of transcription during apoptosis. In case of cellular physiological modifications, e.g. under spermiogenesis or animal hibernation, this process can be reversible [2,3]. Ultrastructural analysis and immune electron microscopy of the aggregates observed in U-937 cell line allowed identification of three types of nuclear particles dominating in these aggregates: interchromatin granules (IGs) of 10 x 40 nm, proteasomes (PRs) of 10-15 × 30 nm, and long perichromatin fibers (PFs) [4]. Both IGs and PRs were rod-like shaped particles of variable size. They demonstrated different immune properties: IGs recognized ABs against the splicing factor SC35 (Figure 1a), meanwhile PRs reacted with antibodies (ABs) against proteins of the proteasome protein complex (Figure 1b). Ultrastructurally PFs observed in this study essentially differed from the ones described earlier [3][4][5][6]. Figure 1Apoptotic cells (ultrastructure and X-ray microanalysis). a-intranuclear aggregate, HERDS, contains interchromatin granules, proteasomes, and perichromatin fibers. Arrows indicate the gold labels of SC35. N-nucleus, C-cytoplasm, NEnuclear envelope, IS-interchromatin space; b-loose aggregate of proteasomes in cytoplasm labeled with pABs against proteasome and immune gold. NP-nuclear pore; c-perichromatin fibers (PFs) (encircled by ovals) in nucleus and cytoplasm; d-histogramm of Na+ and K+ elemental contents in U-937 cells (control n=5, apoptosis n=5). X-ray spectra of elements were collected at accelerating voltage of 80 kv for 300 s. Data shown as means ± SEM.PFs on sections contrasted with uranyl-acetate were seen as elongated electron dense particles 12-13 nm thick with a periodic structure with a period of 10 nm (Figure 1c) [7]. PFs were formed by 4 nm thick hel...

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Section: Figurementioning

confidence: 87%

Ultrastructural Study and X-Ray Microanalysis of Apoptotic Lymphoma Cells U-937

Snigirevskaya¹,

Moshkov²,

Komissarchik³

2017

Biochem Mol biol J

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“…Regulatory molecules that participate in the programmed cell death were identified as proteasome substrates (Low, ). Among the first substrates discovered were proteins with nuclear functions, such as cyclins, inhibitors of cyclin‐dependent kinases, transcription factors (NF‐kB, IkB, p53) (Kisselev et al, ; Enenkel, ).…”

Section: Apoptosis and Proteasomesmentioning

confidence: 99%

Ultrastructural traits of apoptosis

Snigirevskaya

Komissarchik

2019

Cell Biology International

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This review summarizes original and literature data on changes in the ultrastructure of major cell organelles during apoptosis obtained by transmission electron microscopy. Organelles that make the most crucial contribution to the initiation of apoptosis: plasma membrane, mitochondria, proteasomes, Golgi apparatus, and endoplasmic reticulum, were of our prime attention. The nucleus and cytoskeleton that undergo essential changes, were considered as well. Special attention was paid to the data on ultrastructural changes in the cell organelles observed recently by electron microscopic tomography and correlative microscopy, in particular, to remodeling of mitochondrial crista junctions and microtubules during the execution phase of apoptosis.

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“…Кроме протеасом в цитоплазму транспортируются и перихроматиновые фибриллы (ПФ), где они из пре-мРНК созревают в мРНК и, соединяясь с белками, образуют мРНП. Предполагается, что переход ПФ, так же как и протеасом, в цитоплазму происходит через ядерные поры [44,45,156,157]. Это подтверждается исследованием ультратонких срезов, на которых видно, что исчерченные ПФ располагаются в области пор ядерной мембраны клеток, выявляясь со стороны как нуклеоплазмы, так и цитоплазмы (схема 3).…”

Section: апоптоз и ядроunclassified

“…Регуляторные молекулы, которые участвуют в программируемой клеточной смерти, идентифицированы как субстраты протеасом [91]. Среди первых обнаруженных субстратов оказались протеины с ядерными функциями, такие как циклины, ингибиторы циклинзависимых киназ, факторы транскрипции (NF-kB, IkB, p53) [44,45,74].…”

Section: апоптоз и протеасомыunclassified

Ультраструктурные Изменения Внутриклеточных Органелл При Апоптозе

Снигиревская¹,

Комиссарчик²

2018

Biosfera

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Гибель клеток в результате генетически запрограммированных процессов апоптоза принимает участие не только в эмбриогенезе и гистогенезе, но также является фактором патогенеза многих заболеваний, в том числе вызываемых факторами окружающей среды, и может индуцироваться ими. В последнее время на первый план вышли исследования молекулярных механизмов апоптоза. В настоящем обзоре основное внимание уделено современным данным об ультраструктурных особенностях основных клеточных органелл и об их изменениях в процессе апоптоза, в том числе перестройкам компонентов интерхроматинового пространства ядра, а также участию убиквитин-протеасомной системы в апоптозе. Ключевые слова: апоптоз, внутриклеточные органеллы, ультраструктура, хроматин, электронная микроскопия, убиквитин-протеасомная система. Cell death caused by the genetically determined processes known as apoptosis is implicated not only in embryogenesis and cell and tissue turnover but also in the pathogenesis of many diseases including those induced by environmental factors and may be directly induced by some of the latter. In recent years, the elucidation of the molecular mechanisms of apoptosis was taking the central stage as reflected in a numerous reviews. The present review is focused on recent data about the ultrustructural features of cellular organelles upon apoptosis, including first of all the rearrangements of the interchromatin intranuclear space and the involvement of the ubiquitin-proteasome system in apoptosis.

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Proteasome Dynamics: Will the Territory of Proteasomes Be Claimed By Mitochondrial Proteases Under Stress Conditions?

Cited by 3 publications

References 26 publications

Ultrastructural Study and X-Ray Microanalysis of Apoptotic Lymphoma Cells U-937

Ultrastructural Study and X-Ray Microanalysis of Apoptotic Lymphoma Cells U-937

Ultrastructural traits of apoptosis

Ультраструктурные Изменения Внутриклеточных Органелл При Апоптозе

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