9kcf
Bovine Flagellar TRiC
Structural highlights
Publication Abstract from PubMedAs animals evolved from external to internal fertilization, sperm flagella, once transiently propelling sperm in water to reach nearby eggs, developed to beat for days in the viscous female reproductive tract. How flagella are remodeled accordingly remains unclear. Unlike externally fertilizing zebrafish and sea urchins, mammalian flagella feature a barrel between radial spokes (RSs) RS1 and RS2. Here, we show that this RS1-RS2 barrel (RRB) is a unique T-complex protein-1 ring complex (TRiC) that folds locally translated polypeptides to sustain flagellar motility. Cryo-electron microscopy (cryo-EM) reveals a flagellum-specific TRiC structure. An in situ cryo-electron tomography (cryo-ET) map of flagellar axonemes captures the RRB TRiC in an active, substrate-receptive state, with additional densities suggestive of folding substrates and cofactors. Mammalian flagella contain components of translation machineries and locally synthesize proteins. Cross-linking mass spectrometry identifies candidate locally translated axonemal proteins and folding substrates. Furthermore, a TRiC ATPase inhibitor markedly represses mouse sperm motility. Our findings provide insights into flagellar remodeling in internally fertilizing species. Chaperonin TRiC bridges radial spokes for folding locally translated proteins to sustain mammalian sperm flagellar motility.,Meng X, Li L, Lin C, Zhu Y, Feng Y, Zhao Q, Zhao N, Zhou X, Tong Y, Wang S, Yin G, Liu R, Zhang L, Sun F, Yan X, Zhu X, Cong Y Mol Cell. 2026 Apr 2;86(7):1327-1344.e10. doi: 10.1016/j.molcel.2026.03.005. PMID:41932310[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
| ||||||||||||||||||||
