Superresolution Microscopy of the Nuclear Envelope and Associated Proteins

At an early stage in spermiogenesis the acrosomal vacuole and other organelles including ribosomes are located at the basal end of the cell. From here actin must be transported to its future location at the anterior end of the cell. At no stage in the accumulation of actin in the periacrosomal region is the actin sequestered in a membrane-bounded compartment such as a vacuole or vesicle. Since filaments are not present in the periacrosomal region during the accumulation of the actin even though the fixation of these cells is sufficiently good to distinguish actin filaments in thin section, the actin must accumulate in the nonfilamentous state. The membranes in the periacrosomal region, specifically a portion of the nuclear envelope and the basal half of the acrosomal vacuole membrane, become specialized morphologically in advance of the accumulation of actin in this region. My working hypothesis is that the actin in combination with other substances binds to these specialized membranes and to itself and thus can accumulate in the periacrosmoal region by being trapped on these specialized membranes. Diffusion would then be sufficient to move these substances to this region. In support of this hypothesis are experiments in which I treated mature sperm with detergents, glycols, and hypotonic media, which solubilize or lift away the plasma membrane. The actin and its associated proteins remain attached to these specialized membranes. Thus actin can be nonrandomly distributed in cells in a nonfilamentous state presumably by its association with specialized membranes.

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The plant nuclear envelope in focus

Biochemical Society Transactions ◽

10.1042/bst0380307 ◽

2010 ◽

Vol 38 (1) ◽

pp. 307-311 ◽

Cited By ~ 13

Author(s):

Katja Graumann ◽

David E. Evans

Keyword(s):

Nuclear Envelope ◽

Recent Progress ◽

Protein Targeting ◽

Nuclear Pores ◽

Associated Proteins ◽

Pore Domain

Recent progress in understanding the plant NE (nuclear envelope) has resulted from significant advances in identifying and characterizing the protein constituents of the membranes and nuclear pores. Here, we review recent findings on the membrane integral and membrane-associated proteins of the key domains of the NE, the pore domain and inner and outer NEs, together with information on protein targeting and NE function.

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The nuclear envelope

Epigenetics, Nuclear Organization & Gene Function ◽

10.1093/oso/9780198831204.003.0011 ◽

2019 ◽

pp. 140-146

Author(s):

John C. Lucchesi

Keyword(s):

Nuclear Envelope ◽

Lipid Bilayers ◽

Nuclear Membrane ◽

Substantial Portion ◽

Inner Membrane ◽

Double Membrane ◽

Stochastic Nature ◽

Inner Surface ◽

Associated Proteins ◽

Or Gene

The nuclear envelope is a double membrane sheath made up of two lipid bilayers—an outer and an inner membrane. The inner surface of the inner membrane is associated with a meshwork of filaments made up of lamins and of lamin-associated proteins that constitute the lamina. A substantial portion of the genome contacts the lamina through lamina-associated domains (LADs). LADs usually position silent or gene-poor regions of the genome near the lamina and nuclear membrane. The position of some LADs is different in some cells of the same tissue, reflecting the stochastic nature of gene activity; it can also change during differentiation, allowing the necessary activation of particular genes. Contact of transcription units with nuclear pores can result in activation or, sometimes, repression. Some of the proteins that contribute to the structure of the pores can activate transcription by associating with genes or with super-enhancers away from the nuclear membrane.

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Characterization of Onc112 Effect on Ribosomes and Associated Proteins in Live E. coli Cells using Superresolution Microscopy

Biophysical Journal ◽

10.1016/j.bpj.2018.11.1969 ◽

2019 ◽

Vol 116 (3) ◽

pp. 362a

Author(s):

Mainak Mustafi ◽

James C. Weisshaar

Keyword(s):

Superresolution Microscopy ◽

E Coli ◽

Associated Proteins

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Anchorage of Plant RanGAP to the Nuclear Envelope Involves Novel Nuclear-Pore-Associated Proteins

Current Biology ◽

10.1016/j.cub.2007.05.076 ◽

2007 ◽

Vol 17 (13) ◽

pp. 1157-1163 ◽

Cited By ~ 79

Author(s):

Xianfeng Morgan Xu ◽

Tea Meulia ◽

Iris Meier

Keyword(s):

Nuclear Envelope ◽

Nuclear Pore ◽

Associated Proteins

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Decreased torsinA or LINC Complex Function Rescues a Laminopathy in Caenorhabditis elegans

10.1101/2020.04.22.055988 ◽

2020 ◽

Author(s):

Gabriela Huelgas-Morales ◽

Mark Sanders ◽

Gemechu Mekonnen ◽

Tatsuya Tsukamoto ◽

David Greenstein

Keyword(s):

Nuclear Envelope ◽

Complex Function ◽

Nuclear Lamina ◽

Premature Aging ◽

Linc Complex ◽

Force Transmission ◽

Complex Activity ◽

Aaa Atpase ◽

C Elegans ◽

Associated Proteins

AbstractThe function of the nucleus depends on the integrity of the nuclear lamina, an intermediate filament network associated with the linker of nucleoskeleton and cytoskeleton (LINC) complex spanning the nuclear envelope. In turn, the AAA+ ATPase torsinA regulates force transmission from the cytoskeleton to the nucleus. In humans, mutations affecting nuclear envelope-associated proteins cause laminopathies, including progeria, myopathy, and dystonia. We report that decreasing the function of the C. elegans torsinA homolog, OOC-5, rescues the sterility and premature aging caused by a null mutation in the single worm lamin homolog, lmn-1. Loss of OOC-5 activity prevents nuclear collapse in lmn-1 mutants by disrupting the function of the LINC complex. These results suggest that LINC complex-transmitted forces damage nuclei with a compromised nuclear lamina.One Sentence SummaryInhibiting LINC complex activity prevents a progeric syndrome in C. elegans.

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Relationships at the nuclear envelope: lamins and nuclear pore complexes in animals and plants

Biochemical Society Transactions ◽

10.1042/bst0380829 ◽

2010 ◽

Vol 38 (3) ◽

pp. 829-831 ◽

Cited By ~ 31

Author(s):

Jindriska Fiserova ◽

Martin W. Goldberg

Keyword(s):

Nuclear Envelope ◽

Nuclear Periphery ◽

Nuclear Lamina ◽

Nuclear Pore ◽

Nuclear Pore Complexes ◽

Nucleocytoplasmic Trafficking ◽

Animal Cells ◽

Cellular Processes ◽

Associated Proteins ◽

Pore Complexes

The nuclear envelope comprises a distinct compartment at the nuclear periphery that provides a platform for communication between the nucleus and cytoplasm. Signal transfer can proceed by multiple means. Primarily, this is by nucleocytoplasmic trafficking facilitated by NPCs (nuclear pore complexes). Recently, it has been indicated that signals can be transmitted from the cytoskeleton to the intranuclear structures via interlinking transmembrane proteins. In animal cells, the nuclear lamina tightly underlies the inner nuclear membrane and thus represents the protein structure located at the furthest boundary of the nucleus. It enables communication between the nucleus and the cytoplasm via its interactions with chromatin-binding proteins, transmembrane and membrane-associated proteins. Of particular interest is the interaction of the nuclear lamina with NPCs. As both structures fulfil essential roles in close proximity at the nuclear periphery, their interactions have a large impact on cellular processes resulting in affects on tissue differentiation and development. The present review concentrates on the structural and functional lamina–NPC relationship in animal cells and its potential implications to plants.

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Nuclear and nuclear envelope localization of dystrophin Dp71 and dystrophin-associated proteins (DAPs) in the C2C12muscle cells: DAPs nuclear localization is modulated during myogenesis

Journal of Cellular Biochemistry ◽

10.1002/jcb.21870 ◽

2008 ◽

Vol 105 (3) ◽

pp. 735-745 ◽

Cited By ~ 38

Author(s):

R. González-Ramírez ◽

S.L. Morales-Lázaro ◽

V. Tapia-Ramírez ◽

D. Mornet ◽

B. Cisneros

Keyword(s):

Nuclear Envelope ◽

Nuclear Localization ◽

Associated Proteins

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RASCAL Is a New Human Cytomegalovirus-Encoded Protein That Localizes to the Nuclear Lamina and in Cytoplasmic Vesicles at Late Times Postinfection

Journal of Virology ◽

10.1128/jvi.02462-09 ◽

2010 ◽

Vol 84 (13) ◽

pp. 6483-6496 ◽

Cited By ~ 12

Author(s):

Matthew S. Miller ◽

Wendy E. Furlong ◽

Leesa Pennell ◽

Marc Geadah ◽

Laura Hertel

Keyword(s):

Amino Acids ◽

Nuclear Envelope ◽

Human Cytomegalovirus ◽

Nuclear Membrane ◽

Nuclear Lamina ◽

Open Reading Frames ◽

Short Version ◽

Nuclear Egress ◽

Cytoplasmic Vesicles ◽

Associated Proteins

ABSTRACT The products of numerous open reading frames (ORFs) present in the genome of human cytomegalovirus (CMV) have not been characterized. Here, we describe the identification of a new CMV protein localizing to the nuclear envelope and in cytoplasmic vesicles at late times postinfection. Based on this distinctive localization pattern, we called this new protein nuclear r im- as sociated c ytomegalovir al protein, or RASCAL. Two RASCAL isoforms exist, a short version of 97 amino acids encoded by the majority of CMV strains and a longer version of 176 amino acids encoded by the Towne, Toledo, HAN20, and HAN38 strains. Both isoforms colocalize with lamin B in deep intranuclear invaginations of the inner nuclear membrane (INM) and in novel cytoplasmic vesicular structures possibly derived from the nuclear envelope. INM infoldings have been previously described as sites of nucleocapsid egress, which is mediated by the localized disruption of the nuclear lamina, promoted by the activities of viral and cellular kinases recruited by the lamina-associated proteins UL50 and UL53. RASCAL accumulation at the nuclear membrane required the presence of UL50 but not of UL53. RASCAL and UL50 also appeared to specifically interact, suggesting that RASCAL is a new component of the nuclear egress complex (NEC) and possibly involved in mediating nucleocapsid egress from the nucleus. Finally, the presence of RASCAL within cytoplasmic vesicles raises the intriguing possibility that this protein might participate in additional steps of virion maturation occurring after capsid release from the nucleus.

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