First published online January 23, 2008
Journal of Cell Science 121, 301e (2008)
© The Company of Biologists Limited
gp210 breaks it down
In animal cells, the nuclear envelope is broken down and then rebuilt during every cycle of mitosis. During breakdown, multiple components of the envelope – including nuclear pore complexes, the nuclear lamina and nuclear membranes – are dismantled, but how is this process controlled? On page 317, Iain Mattaj and colleagues show that gp210, a transmembrane protein in the nuclear pore complex, is necessary for nuclear envelope breakdown. The authors show that, in early-stage C. elegans embryos, the nuclear lamina cannot depolymerise when gp210 is knocked down or mutated, which gives rise to daughter cells with twinned nuclei. Moreover, antibodies that target gp210 inhibit the breakdown of Xenopus nuclear envelopes in vitro. The authors show that antibody binding reduces phosphorylation of the C-terminal domain of gp210, without altering its localisation or interfering with normal nuclear import. Knocking down cyclin-B–cdc2 (the kinase that is thought to phosphorylate gp210 during mitosis) mimics the phenotype of gp210 depletion in C. elegans. Therefore, the authors propose, phosphorylation of gp210 by cyclin-B–cdc2 may trigger breakdown of the nuclear envelope. Their results shed light on a key early step in mitosis.
Related articles in JCS:
- A role for gp210 in mitotic nuclear-envelope breakdown
- Vincent Galy, Wolfram Antonin, Andreas Jaedicke, Martin Sachse, Rachel Santarella, Uta Haselmann, and Iain Mattaj
JCS 2008 121: 317-328.
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