Affordable Access

Publisher Website

Catenin keeps vesicles close

The Journal of Cell Biology
The Rockefeller University Press
Publication Date
DOI: 10.1083/jcb1635rr3
  • Research Roundup
  • Biology


Research Roundup 929 T EXT B Y W ILLIAM A. W ELLS WELLSW @ ROCKEFELLER . EDU S is for sticky kinase better known for triggering DNA replication also helps create the sticky hetero- chromatin at centromeres of fission yeast, according to Julie Bailis, Susan Forsburg (Salk Institute, La Jolla, CA), and colleagues. The dual action makes sense, as chromosomes must be stuck together as soon as they are replicated. The responsible kinase activity, Hsk1 (CDC7)–Dfp1, is restricted to S phase, when DNA replication takes place. Dfp1 turned up in a two-hybrid screen with Swi6, the fission yeast equivalent of heterochromatin protein 1 (HP1). Cells with a mutant Dfp1 that no longer binds Swi6 can replicate their DNA but suffer segregation errors when their defective centromeres fall apart. Swi6 localization is normal in these cells but, based on in vitro results, Swi6 phosphorylation may be reduced. This is the first indication that Swi6 localization is not sufficient to define hetero- chromatin function. An interesting parallel is known in budding yeast, where establishment of silent heterochromatin at the mating type locus requires passage through S phase, though not DNA replication. Budding yeast lacks an HP1 homologue, but perhaps other proteins serve an equivalent heterochromatic function. � Reference: Bailis, J.M., et al. 2003. Nat. Cell Biol . 10.1038/ncb1069. A Centromeres fall apart (right) without Hsk1 action in S phase. F or sb ur g/ M ac m ill an Worms delay in deep sleep orms deprived of all oxygen can pause, take a deep breath, and enter a suspended animation from which they can emerge unscathed several days later. Now, Mark Roth (Fred Hutchinson Cancer Research Center, Seattle, WA) and colleagues show that these worms use the spindle checkpoint to prevent passage through mitosis during anoxia. This arre

There are no comments yet on this publication. Be the first to share your thoughts.


Seen <100 times