Click here to close Hello! We notice that you are using Internet Explorer, which is not supported by Xenbase and may cause the site to display incorrectly. We suggest using a current version of Chrome, FireFox, or Safari.
Chromosoma 1989 Oct 01;984:233-41. doi: 10.1007/bf00327308.
Show Gene links Show Anatomy links

Functional role of newly formed pore complexes in postmitotic nuclear reorganization.

Benavente R , Dabauvalle MC , Scheer U , Chaly N .

Many nuclear proteins are released into the cytoplasm at prometaphase and are transported back into the daughter nuclei at the end of mitosis. To determine the role of this reentry in nuclear remodelling during early interphase, we experimentally manipulated nuclear protein uptake in dividing cells. Recently we and others have shown that signal-dependent, pore complex-mediated uptake of nuclear protein is blocked in living cells on microinjection of the lectin wheat germ agglutinin (WGA), or of antibodies such as PI1 that are directed against WGA-binding pore complex glycoproteins. In the present study, we microinjected mitotic PtK2 cells with WGA or antibody PI1 and followed nuclear reorganization of the daughter cells by immunofluorescence and electron microscopy. The inhibitory effect on nuclear protein uptake was monitored by co-injection of the karyophilic protein nucleoplasmin. When injected by itself early in mitosis, nucleoplasmin became sequestered into the daughter nuclei as they entered telophase. In contrast, nucleoplasmin was excluded from the daughter nuclei in the presence of WGA or antibody PI1. Although PtK2 cells with blocked nuclear protein uptake completed cytokinesis, their nuclei showed a telophase-like completed cytokinesis, their nuclei showed a telophase-like organization characterized by highly condensed chromatin surrounded by a nuclear envelope containing a few pore complexes. These findings suggest that pore complexes become functional as early as telophase, in close coincidence with nuclear envelope reformation. They further indicate that the extensive structural rearrangement of the nucleus during the telophase-G1 transition is dependent on the influx of karyophilic proteins from the cytoplasm through the pore complexes, and is not due solely to chromosome-associated components.

PubMed ID: 2692995
Article link: Chromosoma

Species referenced: Xenopus
Genes referenced: npm1 ptk2

References [+] :
Benavente, Nucleocytoplasmic sorting of macromolecules following mitosis: fate of nuclear constituents after inhibition of pore complex function. 1989, Pubmed