News & Comment

Centrioles are among the most beautiful of biological structures. How their highly conserved nine-fold symmetry is generated is a question that has intrigued cell biologists for decades. Two recent structural studies provide the tantalizing suggestion that the self-organizing properties of the SAS-6 protein hold the answer.

Defining the scope and venue of a scientific paper requires a balance between the authors' goals for the study and reasonable feedback gleaned through peer review.

The sensors and switches that convert environmental inputs to specific biological outputs inspire the tools chemical biologists engineer and apply to better understand these complex systems.

The GTPase switch is a versatile molecular device used by many proteins, such as the small GTPases, to regulate an astounding number of functions. Although the basics of the guanine nucleotide cycle are now well established, the next challenge is to reach an integrated view of how these proteins use it to orchestrate signaling pathways.

Sensors and reporters are among the most exciting tools used in cell biology. Now, they are increasingly used in developmental biology and medicine because they allow us to spy on events in living cells and organisms, including humans, in real time and with high spatial resolution. Herein, we discuss multiple design options for fluorescent sensors and reporters as well as strategies to improve their properties and increase development.

Lambda's 'genetic switch' responds in a dramatic all-or-none fashion to an environmental signal, activating transcription of certain genes as it turns off others. The switch illustrates principal features of many biological regulatory processes.

In response to decreasing Ca²⁺ levels in the endoplasmic reticulum, STIM proteins couple with Orai channels in the plasma membrane, leading to Ca²⁺ influx into the cell. In addition to Ca²⁺-related endoplasmic reticulum stress, STIM proteins are emerging as general stress sensors that react to multiple stress signals to orchestrate Ca²⁺ signaling and homeostasis.

This Commentary clarifies the meaning of the funnel diagram, which has been widely cited in papers on protein folding. To aid in the analysis of the funnel diagram, this Commentary reviews historical approaches to understanding the mechanism of protein folding. The primary role of free energy in protein folding is discussed, and it is pointed out that the decrease in the configurational entropy as the native state is approached hinders folding, rather than guiding it. Diagrams are introduced that provide a less ambiguous representation of the factors governing the protein folding reaction than the funnel diagram.

Balancing big science projects with smaller-scale mechanistic studies provides a collaborative approach for integrating scientific knowledge and addressing major scientific challenges.