Late Somatic Gene 2 disrupts parental spheroids cooperatively with Volvox hatching enzyme A in Volvox.
Late Somatic Gene 2 disrupts parental spheroids cooperatively with Volvox hatching enzyme A in Volvox.
复制标题
晚期体细胞基因 2 与团藻孵化酶 A 协同破坏亲本球体。
DOI：
10.1007/s00425-016-2599-y
复制
发表时间：
2016
期刊：
影响因子：
4.3
通讯作者：
Hasegawa T
中科院分区：
文献类型：
--
作者：
Nishimura M;Nagashio R;Sato Y;Hasegawa T
主要结论我们发现团藻LSG 2是一种新的裂解酶，它与团藻幼体分泌的VheA协同作用，在亲本细胞外基质中积累并破坏亲本球状体，细胞外基质（ECM）的时空限制性降解对多细胞生物的发育和生存至关重要。在绿色团藻的无性生活史中，幼藻通过亲本ECM的限制性降解在适当的时间从亲本球体中释放出来。在团藻孵化时，裂解酶应该特异性地降解亲本ECM，但对时空限制的亲本降解机制知之甚少。在这里，我们确定了糖蛋白编码的晚期体细胞基因2（LSG 2）作为一种新的溶解酶，积累在父母ECM在孵化前阶段。LSG 2和团藻孵化酶A（VheA）（一种由幼体分泌的丝氨酸蛋白酶）的双重作用导致ECM片层在所有阶段的降解，甚至破坏子球体，而VheA仅在LSG 2积累的孵化前阶段破坏球体，这表明LSG 2和VheA的组合足以导致ECM片层的降解。在孵化前阶段，亲本球状体变得容易受到外部应用的细菌蛋白酶的混合物的蛋白水解，这可以通过LSG 2促进。这些结果表明，LSG 2通过修饰亲本ECM使其脆弱而与VheA协同破坏亲本ECM，并且这些酶的适当活性对于在适当的时机进行亲本特异性ECM降解至关重要。
Main conclusionWe identified LSG2 as a novel lytic enzyme that accumulates in the parental extracellular matrix and disrupts parental spheroids cooperatively with VheA secreted by juveniles inVolvox.Spatiotemporally restricted degradation of extracellular matrix (ECM) is essential for development and survival in multicellular organisms. In an asexual life cycle of green algaeVolvox, juveniles are released from parental spheroids through holes made by restricted degradation of parental ECM at the proper timing. Lytic enzyme(s) should specifically degrade parental ECM uponVolvoxhatching, but little is known about the mechanisms of spatiotemporally restricted parental degradation. Here, we identified a glycoprotein encoded by theLate Somatic Gene 2(LSG2) as a novel lytic enzyme that accumulates in parental ECM during the prehatching stages. The dual action of LSG2 andVolvoxhatching enzyme A (VheA), a serine protease secreted by juveniles, causes the degradation of ECM sheets at all stages and destroys even daughter spheroids, while VheA alone disrupts spheroids only in the prehatching stage when LSG2 is accumulated, suggesting that the combination of LSG2 and VheA is sufficient to cause the degradation of ECM sheet. In the prehatching stage, parental spheroids became susceptible to the proteolysis by a mixture of bacterial proteases applied externally, which could be facilitated by LSG2. These results suggest that LSG2 disrupts parental ECM cooperatively with VheA by modifying the parental ECM to make it fragile, and that the appropriate activity of these enzymes is crucial for the parent-specific ECM degradation at the proper timing.