Localization of Pom121 to the inner nuclear membrane is required for an early step of interphase nuclear pore complex assembly

Funakoshi, Tomoko; Clever, Michaela; Watanabe, Ai; Imamoto, Naoko

doi:10.1091/mbc.e10-07-0641

Cited by 84 publications

(108 citation statements)

References 39 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Because the regulatory interaction between importin-b and POM121 can be reproduced in the absence of cytosl, our results also support the existence of a membrane-associated sub-population of importin-a (Hachet et al, 2004). Recent work has identified five functional NLS motifs in the same general region of one of the human POM121 genes and suggests that these are essential for targeting the protein to the inner nuclear membrane during interphase (Funakoshi et al, 2011). Pulldown experiments performed by Yavuz et al with different fragments of Xenopus POM121 suggest that the two bipartite NLSs of the Xenopus protein form strong interactions with importin-a.…”

Section: Discussionsupporting

confidence: 78%

“…Our findings do not exclude the possibility that the POM121 NLSs might play a separate, import-related function in interphase assembly (Doucet et al, 2010;Funakoshi et al, 2011;Yavuz et al, 2010) (see also Fig. 9C).…”

Section: Discussioncontrasting

confidence: 57%

“…There is conflicting evidence regarding the vital function for each of the three vertebrate membrane Nups in NPC assembly (Antonin et al, 2005;Cohen et al, 2003;Doucet et al, 2010;Drummond and Wilson, 2002;Funakoshi et al, 2011;Mansfeld et al, 2006;Stavru et al, 2006a;Stavru et al, 2006b). Most recently, POM121 has been proposed to play a crucial, ratelimiting role in interphase NPC assembly but not in the postmitotic process (Doucet et al, 2010).…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

A dominant-negative form of POM121 binds chromatin and disrupts the two separate modes of nuclear pore assembly

Shaulov

Gruber

Cohen

et al. 2011

Journal of Cell Science

View full text Add to dashboard Cite

SummaryNuclear pore complexes (NPCs) are formed during two separate stages of the metazoan cell cycle. They are assembled into the reforming nuclear envelope (NE) at the exit from mitosis and into an intact, expanding NE during interphase. Here, we show that a soluble internal fragment of the membrane nucleoporin POM121 has a dominant-negative effect on both modes of assembly in a cell-free reconstitution system. The soluble POM121 fragment binds chromatin at sites that are distinct from ELYS-Nup107-160 'seeding' sites and prevents membrane enclosure and NPC formation. Importin-b negatively regulates chromatin binding by the POM121 fragment through a conserved NLS motif and is also shown to affect the recruitment of the endogenous membrane protein to chromatin in the full assembly system. When an intact NE is present before the addition of the dominant-negative fragment, NPCs are inserted into the NE but membrane expansion is inhibited. This results in densely packed NPCs with no intervening membrane patches, as visualized by scanning electron microscopy. We conclude that POM121 plays an important role in both modes of assembly and links nuclear membrane formation and expansion to nuclear pore biogenesis.

show abstract

Section: Discussionsupporting

confidence: 78%

Section: Discussioncontrasting

confidence: 57%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

A dominant-negative form of POM121 binds chromatin and disrupts the two separate modes of nuclear pore assembly

Shaulov

Gruber

Cohen

et al. 2011

Journal of Cell Science

View full text Add to dashboard Cite

show abstract

“…9 Several groups recently reported the importance of Pom121 for the recruitment of the Nup107-160 complex into new assembly sites of NPC on closed nuclear envelopes. [11][12][13] These observations agree closely with live-cell imaging of NPC formation. 14 Downregulation of Pom121 by Cdkinhibition could be a reason to suppress of Nup107 or Nup133 that was fluorescently labeled and how much excess YFPNup107 or Nup133-YFP was expressed are also critical issues, because they have important implications in the interpretation of the data.…”

Section: Novel Approaches For Investigating Nuclear Growth and Npc Fosupporting

confidence: 82%

Nuclear size, nuclear pore number and cell cycle

Maeshima

Iino

Hihara

et al. 2011

Nucleus

Self Cite

View full text Add to dashboard Cite

In eukaryotic cells, the nucleus is a complex and sophisticated organelle containing genomic DNA and supports essential cellular activities. Its surface contains many nuclear pore complexes (NPCs), channels for macromolecular transport between the cytoplasm and nucleus. It has been observed that the nuclear volume and the number of NPCs almost doubles during interphase in dividing cells, but the coordination of these events with the cell cycle was poorly understood, particularly in mammalian cells. Recently, we demonstrated that cyclin-dependent protein kinases (Cdks) control interphase NPC formation in dividing human cells. Cdks drive the very early step of NPC formation because Cdk inhibition suppressed the generation of "nascent pores," which are considered to be immature NPCs, and disturbed expression and localization of some nucleoporins. Cdk inhibition did not affect nuclear volume, suggesting that these two processes have distinct regulatory mechanisms in the cell cycle. The details of our experimental systems and finding are discussed in more depth. With new findings recently reported, we also discuss possible molecular mechanisms of interphase NPC formation.

show abstract

“…29,38 Moreover, NLSs are found on nups important for early assembly events. [39][40][41][42] Lastly, biochemical intermediates and invaginations of the INM have been observed after the genetic imposition of assembly blocks. [43][44][45] While proteins of the reticulon family 27,28 and nups capable of deforming membranes 46,47 might generate positive membrane curvature that could help form these invaginations, it has been appropriately argued that the generation of negative curvature might be more effective in promoting the formation of a nuclear pore, 48 precisely the kind of curvature that would be compatible with an ESCRT-III mediated mechanism.…”

Section: Does Escrt-iii Directly Contribute To Npc Biogenesis?mentioning

confidence: 99%

ESCRTs breach the nuclear border

Webster

Lusk

2015

Nucleus

View full text Add to dashboard Cite

T he endosomal sorting complexes required for transport (ESCRT) are best known for their role in sorting ubiquitylated membrane proteins into endosomes. The most ancient component of the ESCRT machinery is ESCRT-III, which is capable of oligomerizing into a helical filament that drives the invagination and scission of membranes aided by the AAA ATPase, Vps4, in several additional subcellular contexts. Our recent study broadens the work of ESCRT-III by identifying its role in a quality control pathway at the nuclear envelope (NE) that ensures the normal biogenesis of nuclear pore complexes (NPCs). Here, we will elaborate on how we envision this mechanism to progress and incorporate ESCRT-III into an emerging model of nuclear pore formation. Moreover, we speculate there are additional roles for the ESCRT-III machinery at the NE that broadly function to ensure its integrity and the maintenance of the nuclear compartment.

show abstract

Localization of Pom121 to the inner nuclear membrane is required for an early step of interphase nuclear pore complex assembly

Cited by 84 publications

References 39 publications

A dominant-negative form of POM121 binds chromatin and disrupts the two separate modes of nuclear pore assembly

A dominant-negative form of POM121 binds chromatin and disrupts the two separate modes of nuclear pore assembly

Nuclear size, nuclear pore number and cell cycle

ESCRTs breach the nuclear border

Contact Info

Product

Resources

About