Cells rely on complex signaling networks in which different molecular pathways communicate with one another. Small GTPases act as molecular switches in these networks, controlling diverse cellular processes such as intracellular transport and cell morphogenesis. Although crosstalk between different families of small GTPases is established in animal cells, whether and how such crosstalk occurs in plants has remained largely unknown.

A research team led by Associate Professor Emi Ito and Professor Takashi Ueda at the National Institute for Basic Biology (NIBB), together with collaborators at Ochanomizu University, Kyoto Prefectural University, Saitama University, Nagoya University, and RIKEN, has now uncovered a molecular mechanism that connects two distinct types of small GTPases in the model plant Arabidopsis thaliana. The study was published in Nature Plants.

The researchers identified a protein called REAP1/SWAP70 that links RAB5, a small GTPase involved in intracellular membrane trafficking, with ROP7, a member of the plant-specific ROP (Rho of Plants) family of small GTPases involved in processes such as cell morphogenesis. Their findings reveal a previously unknown RAB5–REAP1–ROP7 signaling pathway and show that this pathway plays an important role in normal pollen development.

Stabilized construction-generated soil is often too alkaline for reuse, while neutralization depends on curing conditions. Although aeration curing is the cheapest way to lower alkalinity, there has been no guidance on when to begin it. Now, researchers from Shibaura Institute of Technology reveal that immediate aeration is preferable when neutralization is the priority, whereas a sealed period is useful when added strength is needed, providing a practical scheduling framework for soil-recycling operations.

Excess fat accumulation in the liver can contribute to the development and progression of metabolic dysfunction-associated steatotic liver disease (MASLD), highlighting the need for new approaches to manage the condition. Now, researchers have found that hyodeoxycholic acid (HDCA), a bile acid, can reduce liver fat in mice while also identifying the biological pathways involved. The findings suggest that HDCA could help inform the development of new approaches to managing MASLD.

How deep is the deepest ocean—and how precisely can we actually measure it? A Japanese research team has mapped the Challenger Deep in the Mariana Trench using the EM124 multibeam echosounder aboard the research vessel Hakuho-maru.

Osaka Metropolitan University researchers developed an AI-driven transfer-learning method that refines volume size factor predictions from first-principles calculations, enabling more reliable prediction of properties in previously unexplored alloy systems.