Berndt C, Casaroli-Marano R P, Vilaró S, Reina M
Department of Cell Biology, University of Barcelona, Spain.
J Cell Biochem. 2001;82(2):246-59. doi: 10.1002/jcb.1119.
Syndecans are cell-surface heparan sulfate proteoglycans, which perform a variety of functions in the cell. Most important, they are co-receptors for growth factors and mediate cell-cell and cell-matrix interactions. Four syndecans (syndecan 1-4) have been described in different species. The aim of this work was the cloning and characterization of human syndecan-3. The human syndecan-3 sequence has high homology to the rat and mouse sequences, with the exception of the 5'-region. Syndecan-3 mRNA is mostly expressed in the nervous system, the adrenal gland, and the spleen. When different cell lines were transiently transfected with full-length syndecan-3 cDNA, it was localized to the membrane and induced the formation of long filopodia-like structures, microspikes, and varicosities. Consequently, the actin cytoskeleton was re-organized, since actin staining was mostly found in the cellular extensions and at the cell periphery, co-localizing with the syndecan-3 staining. The development of the phenotype depended on the presence of sugar chains, as transfected glycosaminoglycan-deficient Chinese hamster ovary (CHO) 745 cells did not show these structural changes, nor did transfected CHO K1 cells in the presence of heparin. The similarity of the cloned DNA sequence with that of other mammalian species and the high expression in the nervous system led us to the assumption that human syndecan-3 could perform comparable functions to those described for syndecan-3 in rat and mouse. Additionally, transient transfection experiments suggest a role of human syndecan-3 in the organization of cell shape by affecting the actin cytoskeleton, possibly by transferring signals from the cell surface in a sugar-dependent mechanism.
Syndecans是细胞表面硫酸乙酰肝素蛋白聚糖，在细胞中发挥多种功能。最重要的是，它们是生长因子的共受体，并介导细胞间和细胞与基质的相互作用。在不同物种中已描述了四种Syndecans（Syndecan 1 - 4）。这项工作的目的是克隆和鉴定人Syndecan - 3。人Syndecan - 3序列与大鼠和小鼠序列具有高度同源性，但5'-区域除外。Syndecan - 3 mRNA主要在神经系统、肾上腺和脾脏中表达。当用全长Syndecan - 3 cDNA瞬时转染不同细胞系时，它定位于细胞膜并诱导形成长丝状伪足样结构、微刺和静脉曲张。因此，肌动蛋白细胞骨架发生了重新组织，因为肌动蛋白染色主要出现在细胞延伸部分和细胞周边，与Syndecan - 3染色共定位。表型的发展取决于糖链的存在，因为转染的缺乏糖胺聚糖的中国仓鼠卵巢（CHO）745细胞未显示这些结构变化，在肝素存在下转染的CHO K1细胞也未显示这些变化。克隆的DNA序列与其他哺乳动物物种的序列相似，且在神经系统中高表达，这使我们推测人Syndecan - 3可能具有与大鼠和小鼠中描述的Syndecan - 3相当的功能。此外，瞬时转染实验表明人Syndecan - 3可能通过影响肌动蛋白细胞骨架，可能通过以糖依赖机制从细胞表面传递信号，在细胞形状的组织中发挥作用。
