SPACA9 and MNMIP1 bridge the seam of spermatid manchette microtubules - PubMed
2 hours ago
- #structural biology
- #spermiogenesis
- #microtubules
- The manchette is a microtubule-based structure crucial for sperm shaping during spermiogenesis, maintaining integrity over several days.
- Cryo-electron tomography shows diverse microtubule ends in the manchette, with CLASP2 present throughout and likely regulating both ends.
- SPACA9 and MNMIP1 bind to the seam of manchette microtubules from the luminal side: SPACA9 binds α- and β-tubulin of protofilament 1, while MNMIP1 binds protofilament 13 and extends through the seam.
- This novel seam MT inner protein complex with a unique binding mode explains how microtubule regulation maintains manchette integrity over time.