Schistosoma mansoni: Sm23 is a transmembrane protein that also contains a glycosylphosphatidylinositol anchor.
Schistosoma mansoni: Sm23 is a transmembrane protein that also contains a glycosylphosphatidylinositol anchor.
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曼氏血吸虫：Sm23 是一种跨膜蛋白，还含有糖基磷脂酰肌醇锚。
DOI：
10.1006/abbi.1994.1146
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发表时间：
1994
影响因子：
3.9
通讯作者：
Strand,M
中科院分区：
文献类型：
--
作者：
Koster,B;Strand,M
Sm23是曼氏血吸虫寄生虫的一种表面蛋白，属于富含半胱氨酸的疏水蛋白家族，表达于哺乳动物的造血细胞或肿瘤细胞上。Sm23具有这些蛋白质高度保守的疏水性，预测有四个跨膜片段，但另外还通过糖基磷脂酰肌醇(GPI)锚点与膜相连。我们的结果表明，Sm23利用潜在的跨膜结构域和GPI锚点进行膜插入：(A)Sm23在被磷脂酰肌醇特异性磷脂酶C(PIPLC)切割后没有从表面释放。(B)在Triton X-114相分离体系中，天然的[~3H]乙醇胺或[35S]蛋氨酸标记的Sm23被分配到洗涤剂相中。当PIPLC去除GPI锚点时，大多数分子停留在洗涤剂相，正如跨膜蛋白所预期的那样。(C)当全长重组Sm23在体外转录和翻译时，多肽链被插入到微粒体膜中：当Sm23在pH为11.5的碳酸盐缓冲液中孵育时，Sm23与膜结合在一起，而膜结合的Sm23不被蛋白酶K消化。(D)重组Sm23在杆状病毒表达系统中表达时，被运送到受感染昆虫细胞的表面，与天然蛋白类似，经PIPLC切割后不释放。
Sm23, a surface protein of the human parasiteSchistosoma mansoni, belongs to the family of "cysteine-rich, hydrophobic proteins," which are expressed on mammalian hematopoietic cells or tumor cells. Sm23 shares the highly conserved hydrophobicity profile of these proteins, which predicts four transmembrane segments, but is in addition linked to the membrane by a glycosylphosphatidylinositol (GPI) anchor. Our results suggest that Sm23 uses both the potential transmembrane domains and the GPI anchor for membrane insertion: (a) Sm23 was not released from the surface after cleavage with phosphatidylinositol-specific phospholipase C (PIPLC). (b) In a Triton X-114 phase-separation system, native [3H]ethanolamine- or [35S]methionine-labeled Sm23 partitioned into the detergent phase. Upon removal of the GPI anchor by PIPLC, the majority of the molecules stayed in the detergent-phase as expected of a transmembrane protein. (c) When full-length recombinant Sm23 was transcribed and translatedin vitro, the polypeptide chain was inserted into microsomal membranes: Sm23 stayed associated with the membranes when they were incubated with carbonate buffer at pH 11.5, and membrane bound Sm23 was protected from digestion with proteinase K. (d) Recombinant Sm23, when expressed in the baculovirus expression system, was transported to the surface of infected insect cells, and similarly to the native protein it was not released from these cells after cleavage with PIPLC.