Kurn Nurith, Duksin Dan
Department of Biophysics, The Weizmann Institute of Science, Rehovot, Israel.
Wilehm Roux Arch Dev Biol. 1982 May;191(3):169-175. doi: 10.1007/BF00848332.
The involvement of protein glycosylation in regulation of the development of the multicellular green alga,Volvox carteri, was studied using the antibiotic, tunicamycin. Three specific developmental processes were found to be affected by the antibiotic: reproductive cell maturation; establishment of polar cellular organization during embryogenesis and release of progeny spheroids from the parental spheroids. Tunicamycin inhibited the transfer of GlcNAc-1-phosphate to dolichyl phosphate which is catalyzed byVolvox membrane preparations. Changes in the glycosylation of several secreted and cellular glycoproteins were observed when proteins were labelled with radioactive amino acids and sugars in the absence and presence of tunicamycin and then electrophoresed on sodium dodecylsulfate-polyacrylamide slab gels. The levels of a few secreted proteins were reduced in tunicamycin treated cultures and one protein band appeared exclusively in the treated cells. Tunicamycin treatment also altered the electrophoretic mobility of radio-iodinated surface macromolecules. Binding of concanavalin A by tunicamycin treatedVolvox spheroids was drastically reduced. It is there-fore likely that the aberrant development results from inhibition of protein glycosylation and the consequent changes in the structure of the cellular, secreted and surface glycoproteins.
利用抗生素衣霉素研究了蛋白质糖基化在多细胞绿藻卡特氏团藻发育调控中的作用。发现抗生素影响三个特定的发育过程：生殖细胞成熟；胚胎发生过程中极性细胞组织的建立以及子代球体从亲代球体中释放。衣霉素抑制了由团藻膜制剂催化的N-乙酰葡糖胺-1-磷酸向多萜醇磷酸的转移。当在不存在和存在衣霉素的情况下用放射性氨基酸和糖标记蛋白质，然后在十二烷基硫酸钠-聚丙烯酰胺平板凝胶上进行电泳时，观察到几种分泌型和细胞型糖蛋白糖基化的变化。在衣霉素处理的培养物中，一些分泌蛋白的水平降低，并且有一条蛋白带仅出现在处理过的细胞中。衣霉素处理还改变了放射性碘化表面大分子的电泳迁移率。衣霉素处理的团藻球体对伴刀豆球蛋白A的结合显著降低。因此，异常发育可能是由于蛋白质糖基化的抑制以及随之而来的细胞、分泌型和表面糖蛋白结构的变化所致。
