کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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1947988 | 1537488 | 2010 | 7 صفحه PDF | دانلود رایگان |

BackgroundThe present research studied the interaction of two ribosome-inactivating proteins (RIPs) from Adenia genus with HeLa cells. Namely, lanceolin and stenodactylin were examined in comparison to volkensin, another toxic two-chain RIP from Adenia genus.MethodsThe binding, endocytosis, intracellular routing, degradation and exocytosis were investigated by measuring the distribution of radiolabelled RIP and by determining its cytotoxicity.ResultsStenodactylin was the most toxic, resulting in the greater inhibition of protein synthesis and cell death. Lanceolin and stenodactylin bound to cells with comparable affinity and have a similar number of binding sites (105/cell). The uptake of lanceolin and stenodactylin was 13 and 36 times greater, respectively, than that reported for volkensin. The two toxins bound to cell membrane receptors via their lectin B chain, were endocytosed through a clathrin-independent pathway, were internalised in a manner independent from endosomal acidification, and required routing through the Golgi apparatus, as reported for modeccin and volkensin. Stenodactylin showed greater uptake, exocytosis and re-uptake of non-degraded RIP than lanceolin and volkensin, whereas volkensin had the highest residual activity after being released from the cell.ConclusionsThe high cytotoxicity of RIPs from the Adenia genus may depend on the following: high affinity binding to the cell and efficient endocytosis, intracellular routing that appears similar to that of other ricin-like toxic RIPs, partial resistance to proteolysis, and, regarding stenodactylin, high accumulation in cell.General significanceThe data provide a model that could lead to new strategies for anti-cancer therapy and neuroscience studies.
Journal: Biochimica et Biophysica Acta (BBA) - General Subjects - Volume 1800, Issue 12, December 2010, Pages 1276–1282