| First Author | Niazi A | Year | 2025 |
| Journal | Dev Cell | Volume | 60 |
| Issue | 5 | Pages | 679-695.e8 |
| PubMed ID | 39657673 | Mgi Jnum | J:363369 |
| Mgi Id | MGI:7856405 | Doi | 10.1016/j.devcel.2024.11.011 |
| Citation | Niazi A, et al. (2024) Microvilli control the morphogenesis of the tectorial membrane extracellular matrix. Dev Cell |
| abstractText | The apical extracellular matrix (aECM), organized by polarized epithelial cells, exhibits complex structures. The tectorial membrane (TM), an aECM in the cochlea mediating auditory transduction, exhibits highly ordered domain-specific architecture. alpha-Tectorin (TECTA), a glycosylphosphatidylinositol (GPI)-anchored ECM protein, is essential for TM organization. Here, we identified that alpha-tectorin is released by distinct modes: proteolytic shedding by TMPRSS2 and GPI-anchor-dependent release from the microvillus tip in mice. In the medial/limbal domain, proteolytically shed alpha-tectorin forms dense fibers. In contrast, in the lateral/body domain, where supporting cells exhibit dense microvilli, shedding restricts alpha-tectorin to the microvillus tip, compartmentalizing collagen-binding sites. Tip-localized alpha-tectorin is released in a GPI-anchor-dependent manner to form collagen-crosslinking fibers, maintaining the spacing and parallel organization of collagen fibrils. Overall, these distinct release modes of alpha-tectorin determine domain-specific organization, with the microvillus coordinating release modes along its membrane to assemble the higher-order ECM architecture. |
