Research
| Title： | Giant proteins in a giant cell: Molecular basis of ultrafast Ca2+-dependent cell contraction |
|---|---|
| First author： | Zhang, Jing; Qin, Weiwei; Hu, Che; Gu, Siyu; Chai, Xiaocui; Yang, Mingkun; Zhou, Fang; Wang, Xueyan; Chen, Kai; Yan, Guanxiong; Wang, Guangying; Jiang, Chuanqi; Warren, Alan; Xiong, Jie; Miao, Wei |
| Journal： | SCIENCE ADVANCES |
| Years： | 2023 |
| DOI： | 10.1126/sciadv.add6550 |
| Abstract： | The giant single-celled eukaryote, Spirostomum, exhibits one of the fastest movements in the biological world. This ultrafast contraction is dependent on Ca2+ rather than ATP and therefore differs to the actin-myosin system in muscle. We obtained the high-quality genome of Spirostomum minus from which we identified the key mo-lecular components of its contractile apparatus, including two major Ca2+ binding proteins (Spasmin 1 and 2) and two giant proteins (GSBP1 and GSBP2), which act as the backbone and allow for the binding of hundreds of spasmins. The evidence suggests that the GSBP-spasmin protein complex is the functional unit of the mesh-like contractile fibrillar system, which, coupled with various other subcellular structures, provides the mechanism for repetitive ultrafast cell contraction and extension. These findings improve our understanding of the Ca2+-depen-dent ultrafast movement and provide a blueprint for future biomimicry, design, and construction of this kind of micromachine. |
