纤毛膜与纤毛囊泡的比较分析  

Comparative Analysis of Ciliary Membranes and Ectosomes

作　　者：Huan Long Fan Zhang Nannan Xu Gai Liu Dennis R.Diener Joel L.Rosenbaum 黄开耀[2] 

机构地区：[1]不详 [2]中国科学院水生生物研究所

出　　处：《科学新闻》2017年第4期128-128,共1页Science News

基　　金：国家自然科学基金;美国国立卫生研究院(NIH)基金的支持

摘　　要：纤毛／鞭毛是突出在真核细胞表面的细胞器，执行着细胞天线的功能，接收胞外信号后激活胞内应答途径，调控细胞的稳态平衡及分化。在单细胞绿藻衣藻和线虫中的研究发现，纤毛可以分泌囊泡至胞外，介导细胞之间的交流。Primary and motile cilia/flagella function as cellular antennae, receiving signals from the environment and subsequently activating signaling pathways that are critical for cellular homeostasis and differentiation [1-3]. Recent work with the green alga Chlamydomonas and the nematode C. elegans demonstrated that ectosomes can be released from the cilium and can mediate the intercellular communication [4-9]. To better understand the function of flagellar ectosomes, we have compared their protein composition to that of the flagellar membrane from which they are derived. Ectosomes released from flagella have a unique protein composition, being enriched in a subset of flagellar membrane proteins, proteases, proteins from the endosomal sorting complex required for transport (ESCRT) [10-12], small GTPases, and ubiquitinated proteins. Live imaging showed that an ESCRT-related protein (PDCD6) was enriched in ectosomes released from flagella during gamete activation. We devised a sensitive and rapid assay to monitor ectosome release using luciferase fused to PDCD6 and a mutated ubiquitin. Ectosome release increased when cells underwent flagellar resorption. Knockdown of two ESCRT-related proteins, PDCD6 and VPS4, attenuated ectosome release during flagellar shortening and shortening was slowed. These data suggest that the ESCRT proteins mediate ectosome release and thereby influence flagellar shortening in Chlamydomonas. In addition, the prevalence of receptors such as agglutinin and ubiquitinated proteins in ciliary ectosomes suggests that they are involved in cell signaling and turnover of ciliary proteins.

关 键 词：细胞器 真核细胞 分化 线虫 绿藻 分泌 

分 类 号：Q244[生物学—细胞生物学]