Abstract：
Although the cell membrane and cytoskeleton play essential roles in cellular morphogenesis, the interaction between the membrane and cytoskeleton is poorly understood. Cotton fibers are extremely elongated single cells, which makes them an ideal model for studying cell development. Here, we used the sphingolipid biosynthesis inhibitor, fumonisin B1 (FB1), and found that it effectively suppressed the myeloblastosis (MYB) transcription factor GhMYB86, thereby negatively affecting fiber elongation. A direct target of GhMYB86 is GhTUB7, which encodes the tubulin protein, the major component of the microtubule cytoskeleton. Interestingly, both the overexpression of GhMYB86 and GhTUB7 caused an ectopic microtubule arrangement at the fiber tips, and then leading to shortened fibers. Moreover, we found that GhMBE2 interacted with GhMYB86 and that FB1 and reactive oxygen species induced its transport into the nucleus, thereby enhancing the promotion of GhTUB7 by GhMYB86. Overall, we established a GhMBE2-GhMYB86-GhTUB7 regulation module for fiber elongation and revealed that membrane sphingolipids affect fiber elongation by altering microtubule arrangement.
摘要：
尽管细胞膜和细胞骨架在细胞形态发生中起着至关重要的作用，细胞膜和细胞骨架之间的相互作用知之甚少。棉纤维是极其细长的单细胞，这使得它们成为研究细胞发育的理想模型。这里,我们使用了鞘脂生物合成抑制剂，伏马菌素B1（FB1），并发现它有效地抑制了成髓细胞病（MYB）转录因子GhMYB86，从而对纤维伸长产生负面影响。GhMYB86的直接靶标是GhTUB7，它编码微管蛋白，微管细胞骨架的主要组成部分。有趣的是,GhMYB86和GhTUB7的过表达都导致纤维尖端的异位微管排列，然后导致纤维缩短。此外，我们发现GhMBE2与GhMYB86相互作用，FB1和活性氧诱导其转运到细胞核中，从而加强GhMYB86对GhTUB7的推广。总的来说,我们建立了用于纤维伸长的GhMBE2-GhMYB86-GhTUB7调节模块，并揭示了膜鞘脂通过改变微管排列来影响纤维伸长。
