Volume 6 Issue 7, July 2004

NUDEL was first identified as a protein required for nuclear migration in filamentous fungi. Now, a study shows that it is important for normal assembly of neurofilaments in the mammalian nervous system. In utero knockdown of NUDEL expression results in disruption of neurofilament organization.

When cellular proteins are attached to a Lys 48-linked polyubiquitin chain, the proteasome will usually degrade them. But attaching such a chain to a yeast transcription factor inhibits its activity without degradation, raising questions about how polyubiquitination regulates transcriptional activation and why the protein is spared destruction.

The invariant duplication of the centriole once per cell cycle is critical for cell division. SAS-5 is the most recent of three coiled-coil centriolar proteins found to be required for centriole duplication in Caenorhabditis elegans.

The ATM and ATR protein kinases are important mediators of the cellular response to DNA damage. They regulate multiple cellular functions as part of a stress response programme, including the activation of cell-cycle checkpoints, DNA replication, DNA repair and DNA recombination. A provocative new study suggests that ATM and ATR also regulate normal DNA replication in unperturbed cells.

Understanding the regulation of β-catenin, a key component of the Wnt signalling pathway, has important implications for developmental processes, maintenance of stem cells and the formation of many cancers. The latest report suggests that a nuclear complex consisting of Pygopus and Legless is required for β-catenin's nuclear localization, thereby promoting its transcriptional activity.