Analysis of Drosophila and mouse mutants reveals that Peroxidasin is required for tissue mechanics and full viability.
Analysis of Drosophila and mouse mutants reveals that Peroxidasin is required for tissue mechanics and full viability.
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对果蝇和小鼠突变体的分析表明，过氧化物酶是组织力学和完整活力所必需的。
DOI：
10.1101/2023.07.19.549730
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发表时间：
2023
期刊：
影响因子：
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通讯作者：
Page-McCaw,Andrea
中科院分区：
文献类型：
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作者：
Peebles,KElkie;LaFever,KimberlyS;Page-McCaw,PatrickS;Colon,Selene;Wang,Dan;Stricker,AubrieM;Ferrell,Nicholas;Bhave,Gautam;Page-McCaw,Andrea
基底膜是细胞外基质薄而结实的薄片。它们为上皮、肌肉、神经和血管等组织提供机械和生化支持。基底膜的力学特性部分是由胶原IV （Col4）赋予的，胶原IV是基底膜上丰富的蛋白质，通过头对头和尾对尾的相互作用形成广泛的二维网络。当Col4网络被组装成基膜后，它被基质上的过氧化物酶交联，形成一个大的共价聚合物。过氧化物酶和Col4交联是高度保守的，表明它们是必需的，但纯合突变小鼠具有温和的表型。为了探索过氧化物酶的作用，我们分析了果蝇的突变体，包括一个新产生的催化null，发现纯合子大多是致命的，只有13%的存活逃逸子。对小鼠突变体的孟德尔分析也显示出类似的模式，纯合子显示出50%的致死率和50%的逃逸率。尽管存在强突变，纯合逃逸子的Col4交联水平较低，但可检测到，这表明存在低效的替代机制，可能是导致存活逃逸子的原因。此外，果蝇突变体的表型与硬度的降低一致。有趣的是，我们发现即使在成年基底膜组装和交联后，过氧化物酶仍然需要保持硬度。这些结果表明过氧化物酶交联可能比以前认为的更重要。
Basement membranes are thin strong sheets of extracellular matrix. They provide mechanical and biochemical support to epithelia, muscles, nerves, and blood vessels, among other tissues. The mechanical properties of basement membranes are conferred in part by Collagen IV (Col4), an abundant protein of basement membrane that forms an extensive two-dimensional network through head-to-head and tail-to-tail interactions. After the Col4 network is assembled into a basement membrane, it is crosslinked by the matrix-resident enzyme Peroxidasin to form a large covalent polymer. Peroxidasin and Col4 crosslinking are highly conserved, indicating they are essential, but homozygous mutant mice have mild phenotypes. To explore the role of Peroxidasin, we analyzed mutants in Drosophila, including a newly generated catalytic null, and found that homozygotes were mostly lethal with 13% viable escapers. A Mendelian analysis of mouse mutants shows a similar pattern, with homozygotes displaying ~50% lethality and ~50% escapers. Despite the strong mutations, the homozygous escapers had low but detectable levels of Col4 crosslinking, indicating that inefficient alternative mechanisms exist and that are probably responsible for the viable escapers. Further, fly mutants have phenotypes consistent with a decrease in stiffness. Interestingly, we found that even after adult basement membranes are assembled and crosslinked, Peroxidasin is still required to maintain stiffness. These results suggest that Peroxidasin crosslinking may be more important than previously appreciated.