Multi-directional activity control of cellular processes as a new tool

Cells need for reactions on environmental changes and a balanced system of signaling cascades within the cell. Proteins outside of the cell, on the cellular surface, inside the cellular membrane, and within the cell orchestrate many fine-tuned signaling pathways, which result in adequate reactions on the environmental conditions or changes in the organism itself.

The spatio-temporal organization of cellular processes, for example, cell signaling, cell polarization and neurite outgrowth, is often regulated by the subcellular distribution of molecules or organelles.

Individual proteins can perform distinct functions when located at different subcellular locations. One example is Rac1 protein, which controls the shape of the skeleton of the cell at the intracellular plasma membrane, but when it localizes in the nucleus it regulates nuclear morphology. The nucleocytoplasmic shuttling of Rac1 plays an important role in tumor invasion. In neurons, the bidirectional transport along axonal microtubules plays a critical role in the proper subcellular distribution of organelles. Its misregulation is involved in neurodegenerative diseases. However, the analysis of complex processes that involve cycling, trafficking or shuttling of signal molecules/organelles between different cell compartments remains a major challenge.

The group of Yaowen Wu, who became recently professor at the department of Chemistry at Umeå University, has now developed a new technology termed "Multi-directional Activity Control (MAC)," which makes live studies of cell signaling processes possible. The researchers are pioneers in developing methods for realtime observation of cellular mechanisms under controlled conditions. They used a photoactivatable, dual-chemically induced dimerization (pdCID) system to control the positioning of organelles and proteins at multiple locations in a single cell.

NewsCatherine Lamontagne