Yamamoto Yukiyo, Grubisic Kristina, Oelgeschläger Michael
Max-Planck Institute of Immunobiology, Stübeweg 51, Freiburg D-79108, Germany.
Differentiation. 2007 Mar;75(3):235-45. doi: 10.1111/j.1432-0436.2006.00134.x.
The tetraspanin family of four-pass transmembrane proteins has been implicated in fundamental biological processes, including cell adhesion, migration, and proliferation. Tetraspanins interact with various transmembrane proteins, establishing a network of large multimolecular complexes that allows specific lateral secondary interactions. Here we report the identification and functional characterization of Xenopus Tetraspanin-1 (xTspan-1). At gastrula and neurula, xTspan-1 is expressed in the dorsal ectoderm and neural plate, respectively, and in the hatching gland, cement gland, and posterior neural tube at tailbud stages. The expression of xTspan-1 in the early embryo is negatively regulated by bone morphogenetic protein (BMP) and stimulated by Notch signals. Microinjection of xTspan-1 mRNA interfered with gastrulation movements and reduced ectodermal cell adhesion in a cadherin-dependent manner. Morpholino knock-down of endogenous xTspan-1 protein revealed a requirement of xTspan-1 for gastrulation movements and primary neurogenesis. Our data suggest that xTspan-1 could act as a molecular link between BMP signalling and the regulation of cellular interactions that are required for gastrulation movements and neural differentiation in the early Xenopus embryo.
四跨膜蛋白家族的四次跨膜蛋白参与了包括细胞黏附、迁移和增殖在内的基本生物学过程。四跨膜蛋白与各种跨膜蛋白相互作用，形成一个大型多分子复合物网络，允许特定的侧向二级相互作用。在此，我们报告非洲爪蟾四跨膜蛋白-1（xTspan-1）的鉴定及其功能特征。在原肠胚和神经胚阶段，xTspan-1分别在背侧外胚层和神经板中表达，在尾芽期则在孵化腺、黏腺和后神经管中表达。xTspan-1在早期胚胎中的表达受到骨形态发生蛋白（BMP）的负调控，并受到Notch信号的刺激。显微注射xTspan-1 mRNA会干扰原肠胚形成运动，并以钙黏蛋白依赖的方式降低外胚层细胞黏附。对内源性xTspan-1蛋白进行吗啉代敲低显示，原肠胚形成运动和初级神经发生需要xTspan-1。我们的数据表明，xTspan-1可能作为BMP信号与早期非洲爪蟾胚胎原肠胚形成运动和神经分化所需的细胞相互作用调节之间的分子联系。
