Volume 8 Issue 5, May 2007

Intriguing parallels in the organization of stem-cell niches have been revealed between plants and animals. Recent evidence indicates that stem cells in multicellular organisms can be specified by kingdom-specific patterning mechanisms that connect to a related core of epigenetic stem-cell factors.

The endosomal sorting complex required for transport (ESCRT) machinery facilitates the sorting of proteins that are destined for lysosomal degradation into multivesicular bodies. Recent structural and functional studies provide new insights into the regulation of this machinery and the biogenesis of multivesicular bodies.

Transformations from one tissue type to another are an established set of phenomena that can be explained by the principles of developmental biology. So, can we deliberately reprogramme cells from one tissue type to another to generate new therapies for human diseases?

The spindle-assembly checkpoint is a safety device that monitors the attachment of spindle microtubules to kinetochores and ensures the fidelity of chromosome segregation in mitosis. Molecular studies are finally starting to reveal the mechanisms of checkpoint activation and inactivation.

Recent data on the genetic and molecular basis of progeroid syndromes have shed light onto the nuclear metabolic defects that might accelerate ageing. What are the mechanistic features of progeroid syndromes? And how can these findings help us understand normal ageing?

The apoptosome is a cytosolic signalling platform that integrates intracellular death signals. The formation of the apoptosome and the activation of its effector, caspase-9, reveal a sophisticated mechanism that might be more common than was initially thought.

Transport of soluble proteins into the nucleus depends either on binding a protein-transport complex or on being small enough to diffuse in. Recent studies indicate that the delivery of integral membrane proteins into the inner nuclear membrane is governed by the same rules.