Department of Cell Biology, Duke University Medical Center, Durham, United States.
University Program in Genetics and Genomics, Duke University, Durham, United States.
Elife. 2020 Oct 14;9:e58107. doi: 10.7554/eLife.58107.
Multiple nuclei sharing a common cytoplasm are found in diverse tissues, organisms, and diseases. Yet, multinucleation remains a poorly understood biological property. Cytoplasm sharing invariably involves plasma membrane breaches. In contrast, we discovered cytoplasm sharing without membrane breaching in highly resorptive rectal papillae. During a six-hour developmental window, 100 individual papillar cells assemble a multinucleate cytoplasm, allowing passage of proteins of at least 62 kDa throughout papillar tissue. Papillar cytoplasm sharing does not employ canonical mechanisms such as incomplete cytokinesis or muscle fusion pore regulators. Instead, sharing requires gap junction proteins (normally associated with transport of molecules < 1 kDa), which are positioned by membrane remodeling GTPases. Our work reveals a new role for apical membrane remodeling in converting a multicellular epithelium into a giant multinucleate cytoplasm.
多种细胞核共享一个共同的细胞质存在于不同的组织、生物和疾病中。然而，多核化仍然是一个了解甚少的生物学特性。细胞质共享必然涉及质膜破裂。相比之下，我们在高度吸收的直肠乳头中发现了没有膜破裂的细胞质共享。在六个小时的发育窗口期间，100 个单个的乳突细胞组装一个多核细胞质，允许至少 62kDa 的蛋白质通过整个乳突组织。乳突细胞质共享不采用典型的机制，如不完全胞质分裂或肌肉融合孔调节剂。相反，共享需要间隙连接蛋白（通常与小于 1kDa 的分子的运输有关），这些蛋白由膜重塑 GTP 酶定位。我们的工作揭示了顶端膜重塑在将多细胞上皮转化为巨大多核细胞质中的新作用。
