A GM1b/asialo-GM1 oligosaccharide-binding R-type lectin from purplish bifurcate mussels Mytilisepta virgata and its effect on MAP kinases
A GM1b/asialo-GM1 oligosaccharide-binding R-type lectin from purplish bifurcate mussels Mytilisepta virgata and its effect on MAP kinases
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DOI：
10.1111/febs.15154
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发表时间：
2019-12-24
期刊：
影响因子：
5.4
通讯作者：
Ozeki, Yasuhiro
中科院分区：
文献类型：
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作者：
Fujii, Yuki;Gerdol, Marco;Ozeki, Yasuhiro
从紫叉贻贝中分离得到一种15 kDa的凝集素，命名为SEVIL。SEVIL形成一种非共价二聚体，与神经节苷脂系列GM1b寡糖(Neu5Aca2-3Gal Beta 1-3GalNAc Beta 1-4Glc)及其前体asialo-GM1(Gal Beta 1-3GalNAc Beta 1-4Glc)强烈结合。SEVIL还与SSEA-4六糖的糖链部分(Neu5Acα2-3Galβ1-3GalNAc beta 1-3GalAlpha 1-4Gal beta 1-4Glc)弱相互作用。用质谱仪测定了该凝集素的部分蛋白质序列，并通过转录分析鉴定了其完整序列。SEVIL由129个氨基酸组成，根据该折叠的QxW基序特征，被归类为R(Icin B)型凝集素。Sevil mRNA在鳃组织中高度表达，特别是在外套膜边缘组织中表达。在Mytildae科的其他物种中也发现了同源序列，其中包括Mytilus galloarticialis，我们在以前的研究中从这些物种中分离出了凝集素MytiLec-1并进行了鉴定。因此，Mytild物种包含至少两个不同家族的凝集素(R型凝集素和Mytilectins)，这两个家族具有共同的β-三叶折叠结构，但具有不同的糖结合特异性。SEVIL对细胞表面含有asialo-GM1寡糖的各种培养细胞株(人乳腺癌、卵巢癌和结肠癌；狗肾)显示出显著的细胞毒性(凋亡)效应。这种细胞毒作用可被抗Asialo-GM1寡糖抗体抑制。在HeLa卵巢癌细胞中，SEVIL呈剂量和时间依赖性地激活MKK3/6、p38MAPK和caspase-3/9。SEVIL通过神经节苷脂低聚糖激活的信号转导通路触发了细胞凋亡。
A 15-kDa lectin, termed SeviL, was isolated from Mytilisepta virgata (purplish bifurcate mussel). SeviL forms a noncovalent dimer that binds strongly to ganglio-series GM1b oligosaccharide (Neu5Aca2-3Gal beta 1-3GalNAc beta 1-4Gal beta 1-4Glc) and its precursor, asialo-GM1 (Gal beta 1-3GalNAc beta 1-4Gal beta 1-4Glc). SeviL also interacts weakly with the glycan moiety of SSEA-4 hexaose (Neu5Ac alpha 2-3Gal beta 1-3GalNAc beta 1-3Gal alpha 1-4Gal beta 1-4Glc). A partial protein sequence of the lectin was determined by mass spectrometry, and the complete sequence was identified from transcriptomic analysis. SeviL, consisting of 129 amino acids, was classified as an R(icin B)-type lectin, based on the presence of the QxW motif characteristic of this fold. SeviL mRNA is highly expressed in gills and, in particular, mantle rim tissues. Orthologue sequences were identified in other species of the family Mytilidae, including Mytilus galloprovincialis, from which lectin MytiLec-1 was isolated and characterized in our previous studies. Thus, mytilid species contain lectins belonging to at least two distinct families (R-type lectins and mytilectins) that have a common beta-trefoil fold structure but differing glycan-binding specificities. SeviL displayed notable cytotoxic (apoptotic) effects against various cultured cell lines (human breast, ovarian, and colonic cancer; dog kidney) that possess asialo-GM1 oligosaccharide at the cell surface. This cytotoxic effect was inhibited by the presence of anti-asialo-GM1 oligosaccharide antibodies. With HeLa ovarian cancer cells, SeviL showed dose- and time-dependent activation of kinase MKK3/6, p38 MAPK, and caspase-3/9. The transduction pathways activated by SeviL via the glycosphingolipid oligosaccharide were triggered apoptosis.