Nuclear basket regulates the distribution and mobility of nuclear pore complexes in yeast
The Dultz group (IBC) recently published their first paper in MBoC, in collaboration with the Weiss Group (Polytechnique Montréal, Canada), revealing how NPCs show different behaviour in mobility and distribution around the nuclear envelope depending on their composition.
The nuclear pore complex (NPC) is the transfer gate for a plethora of biological compounds from the nucleus to the cytoplasm and vice versa. Next to its function as a transport channel, the gigantic complex is also involved in regulating chromatin integrity and gene expression. In the past years it has become evident that NPCs differ in their composition, not only between cell types but also on a single cell level.
In order to shed more light on these differences, the researchers used budding yeast, which harbour at least two variants of NPCs: fully assembled ones and those that lack some proteins of the nuclear basket, a flexible appendage located at the nuclear side of the NPC. They used recombination-induced-tag-exchange to visualize the localization and dynamics of single NPCs in living cells, and found that NPCs move faster within the nuclear envelope when the basket proteins Mlp1 and Mlp2 are missing. It has previously been shown that fully assembled NPCs containing Mlp1 and Mlp2 avoid the nuclear envelope region adjacent to the nucleolus. In this work, the Dultz group found that pores change their localization behaviour with respect to the nucleolus depending on the presence of Mlp1 or Nup2 at the nuclear basket. These observations suggest that fully assembled NPCs share connections to the non-nucleolar territory which may restrict them from moving freely within the nuclear envelope.
Link to the paper in external page "Molecular Biology of the Cell"