Opinion in 2006

It is surely time for water to take up its rightful position as the most important and active of all biological molecules. Liquid water is highly versatile — it can control, for example, the folding, structure, activity and interactions of macromolecules.

The SUN-domain family of nuclear envelope proteins interacts with KASH-domain proteins, which are also nuclear envelope proteins, to form 'bridges' across the inner and outer nuclear membranes. SUN-domain proteins are now proposed to provide a mechanical connection between the nucleoskeleton and the cytoskeleton.

What is the driving force behind periodic biological oscillations such as the circadian, hibernation and sleep–wake cycles? Temporal compartmentalization of metabolism has been shown in budding yeast, and might form the underlying basis for many of the rhythmic phenomena in biology.

Several non-coding RNAs that regulate eukaryotic mRNA transcription have recently been discovered. Their mechanisms of action and biological roles are extremely diverse, which indicates that, so far, we have only had a glimpse of this new class of regulatory factor.

What makes a stem cell is still poorly understood. Recent studies have uncovered that chromatin might hold some of the keys to how embryonic stem cells maintain their pluripotency, their ability to self-renew and induce lineage specification.

Lipid rafts, if they exist in resting cell membranes, are too small to be resolved by fluorescent microscopy and have no defined ultrastructure. However, recent studies with model membranes, computational modelling and innovative cell-biology techniques have provided new insights into plasma-membrane micro-organization.

Lipid droplets are the main lipid store in eukaryotic cells. Although the term lipid droplet is widely used, a unified nomenclature is lacking. So, could the terminology be consolidated? And what recent developments have there been in the field of lipid droplets?