2026-03-11 バージニア工科大学（Virginia Tech）
These are both liquid and frozen water droplets. They are at the same temperature, but the frozen droplets contain an ice nucleator. Photo courtesy of Boris Vinatzer.
＜関連情報＞
- https://news.vt.edu/articles/2026/03/ice-nucleation-fungi-boris-vinatzer-xiaofeng-wang.html
- https://www.science.org/doi/10.1126/sciadv.aed9652
細菌起源の、これまで認識されていなかった真菌の氷核タンパク質 A previously unrecognized class of fungal ice-nucleating proteins with bacterial ancestry
Rosemary J. Eufemio, Mariah Rojas, Kaden Shaw, Ingrid de Almeida Ribeiro, […] , and Konrad Meister
Science Advances Published:11 Mar 2026
Abstract
Ice-nucleating proteins (INpros) catalyze ice formation at high subzero temperatures, with major biological and environmental implications. While bacterial INpros have been structurally characterized, their counterparts in other organisms have remained largely unknown. Here, we identify membrane-independent proteins in fungi of the Mortierellaceae family that promote ice formation with high efficiency. These proteins are predicted to adopt β-solenoid folds and multimerize to form extended ice-binding surfaces, exhibiting mechanistic parallels with bacterial INpros. Structural modeling, phylogenetic analysis, and heterologous gene expression leading to ice nucleation in Escherichia coli and Saccharomyces cerevisiae show that the fungal INpros are encoded by orthologs of the bacterial InaZ gene, which was likely acquired by a fungal ancestor through horizontal gene transfer. The discovery of cell-free fungal INpros provides tools for innovative freezing applications and reveals biophysical constraints on ice nucleation across life.
