Knowing when to let go

Knowing when to let go

uring meiosis I, some mechanism must allow homologous chromosomes to separate while keeping sister chromatids paired until meiosis II. How does a cell make this distinction? On page 219, Rogers et al. propose that in C. elegans the aurora-B kinase AIR-2 is largely responsible for ensuring that cohesion between chromosomes breaks down at the proper place and time. The authors also identified add...

Behavior: Knowing When to Walk Away, Knowing When to Run

A new model has been proposed indicating that humans and other animals weigh the metabolic cost of pursuit in deciding how fast to move toward a given reward, providing a powerful framework for understanding behavior.

Cohesin resolves to let go

or microtubule asters, just as with life in general, sometimes you get stuck in a corner. And, say Cendrine Faivre-Moskalenko and Marileen Dogterom (FOM Institute for Atomic and Molecular Physics, Amsterdam, Netherlands), it can take a catastrophe to get things moving again. Dogterom has been trying to reproduce aster behavior in the minimal environment of a microfabricated chamber. Her beads, ...

Crossing over to let go

A function for multisite phosphorylation Many transcription factors are regulated by phosphorylation on multiple residues. Mylona et al. analyzed multisite phosphorylation in the transcription factor Elk-1 and showed that it may protect against excessive activation (see the Perspective by Whitmarsh and Davis). Phosphorylation by the kinase ERK2 occurred at eight sites, but the sites were phosph...

Knowing When to Stop