scholarly journals FORMATION AND DISTRIBUTION OF NUCLEAR PORE COMPLEXES IN INTERPHASE

1971 ◽  
Vol 51 (2) ◽  
pp. 405-418 ◽  
Author(s):  
Gerd G. Maul ◽  
Joseph W. Price ◽  
Michael W. Lieberman

The possibility of nuclear pore formation in the interphase nucleus was investigated in control and phytohemagglutinin (PHA) stimulated lymphocytes by the freeze-etching technique. 48 hr after the addition of PHA, the newly formed blasts which had not as yet divided had at least twice the number of pores per nucleus as controls. This clearly demonstrates that in lymphocytes nuclear pore formation can take place during interphase. It has generally been assumed that the distribution of nuclear pore complexes in somatic animal cells is random. However, we have utilized freeze etched rat kidney cells and a computer program to evaluate pore distribution. We find a minimum pore center-to-center spacing of approximately 1300 A and multiples thereof with high frequency. This is strong evidence for a nonrandom distribution of nuclear pores. The nonrandomness may be related to an underlying chromosomal organization in interphase. Using three criteria for identifying prospective pore sites (membrane specialization, nonrandomness, and alteration of heterochromatin distribution), we have found forming pores in sectioned material from cultured human melanoma cells. While nuclear pore formation may take place in conjunction with reformation of the nuclear membrane, a mechanism also exists for their formation during interphase.

Author(s):  
Brian Burke

The nuclear envelope is a complex membrane structure that forms the boundary of the nuclear compartment in eukaryotes. It regulates the passage of macromolecules between the two compartments and may be important for organizing interphase chromosome architecture. In interphase animal cells it forms a remarkably stable structure consisting of a double membrane ouerlying a protein meshwork or lamina and penetrated by nuclear pore complexes. The latter form the channels for nucleocytoplasmic exchange of macromolecules, At the onset of mitosis, however, it rapidly disassembles, the membranes fragment to yield small vesicles and the lamina, which is composed of predominantly three polypeptides, lamins R, B and C (MW approx. 74, 68 and 65 kDa respectiuely), breaks down. Lamins B and C are dispersed as monomers throughout the mitotic cytoplasm, while lamin B remains associated with the nuclear membrane vesicles.


2010 ◽  
Vol 38 (3) ◽  
pp. 829-831 ◽  
Author(s):  
Jindriska Fiserova ◽  
Martin W. Goldberg

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.


2007 ◽  
Vol 1109 (1) ◽  
pp. 519-530 ◽  
Author(s):  
J. WESIERSKA-GADEK ◽  
A. KLIMA ◽  
O. KOMINA ◽  
C. RANFTLER ◽  
P. INVERNIZZI ◽  
...  

2002 ◽  
Vol 158 (1) ◽  
pp. 53-62 ◽  
Author(s):  
Sheona P. Drummond ◽  
Katherine L. Wilson

We tested the hypothesis that gp210, an integral membrane protein of nuclear pore complexes (NPCs), mediates nuclear pore formation. Gp210 has a large lumenal domain and small COOH-terminal tail exposed to the cytoplasm. We studied the exposed tail. We added recombinant tail polypeptides to Xenopus nuclear assembly extracts, or inhibited endogenous gp210 tails using anti-tail antibodies. Both strategies had no effect on the formation of fused flattened nuclear membranes, but blocked NPC assembly and nuclear growth. Inhibited nuclei accumulated gp210 and some nucleoporin p62, but failed to incorporate nup214/CAN, nup153, or nup98 and were defective for nuclear import of lamin B3. Scanning and transmission EM revealed a lack of “closely apposed” inner and outer membranes, and the accumulation of novel arrested structures including “mini-pores.” We conclude that gp210 has early roles in nuclear pore formation, and that pore dilation is mediated by gp210 and its tail-binding partner(s). We propose that membrane fusion and pore dilation are coupled, acting as a mechanism to control nuclear pore size.


2000 ◽  
Vol 36 ◽  
pp. 75-88 ◽  
Author(s):  
Michael P. Rout ◽  
John D. Aitchison

2021 ◽  
Vol 545 ◽  
pp. 138-144
Author(s):  
Yueyue Jing ◽  
Yilin Lv ◽  
Jingya Ye ◽  
Longfang Yao ◽  
Liwen Chen ◽  
...  

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