Structure and Function of the Octocoral Sinularia lochmodes lectin

八珊瑚 Lochmodes 凝集素的结构和功能

• 批准号: 12460094
• 负责人: KAMIYA Hisao
• 金额: $ 6.02万
• 依托单位: School of Fisheries Sciences, Kitasato University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 2000
• 资助国家: 日本
• 起止时间: 2000 至 2002
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-12460094/
• 关键词: lectin; D-galactose-binding; octocoral; Sinularia; Symbiodinium; symbiosis; 八放サンゴ

The cDNA cloning of SLL-2, a D-galactose-binding lectin of the octocoral Sinularia lochmodes, has revealed that SLL-2 had a sequence homology to those of "discoidin" group lectins. It is observed that the difference of 2 kD in the molecular weight of SLL-2 was present between that calculated from the deduced amino acid sequence of SLL-2 (10, 751) and that observed in SDS-PAGE(15, 000) and TOF-MS (13, 194). No neutral sugar was observed. On the other hand, the spectroscopic analysis and also a treatment with tyrosinase suggested the presence of dopa in a lectin molecule. SLL-2 seems to have a melanin-like component in the C-terminal region.SLL-2 binds to cell surface of Symbiodinium cell. In this research, we tested the effect of SLL-2 to various dinoflagellates. Additions of ecologically relevant concentrations to the cultures of actively swimming Symbiodinium sp. (Type C) decreased number of the motile cells dramatically, and Symbiodinium cells begun to transform into stationary coccoid form while cell division was not affected. Non-symbiotic dinoflagellates also responded to SLL-2. Gymnodinium catenatum and Prolocentrum micans resulted in cell death after inflation and burst of the cells within 24 hours. Thus, present results strongly suggest that the lectin-mediated chemical signal contributes to a stable symbiosis between S. lochomodes and Symbiodinium. This is the first evidence of chemical recognition and physiological modulation observed between symbiotic dinoflagellates and a coral.The screening for the similar component in the ocotocorals using rabbit antibodies against SLL-2 revealed that SLL-2 seems to be specific to the genus Sinularia.

SLL-2的cDNA克隆是八角形sinularia lochmodes的D-半乳糖结合凝集素的d-半乳糖结合凝集素，它揭示了SLL-2与“盘中”基团凝集素的序列同源性具有序列同源性。可以观察到，从SLL-2的推导氨基酸序列（10，751）计算出的SLL-2分子量中的2 kD差异，并且在SDS-PAGE（15，000）和TOF-MS（13，194）中观察到。未观察到中性糖。另一方面，光谱分析以及用酪氨酸酶进行治疗表明在凝集素分子中存在DOPA。 SLL-2在C末端区域似乎具有类似黑色素的成分。SLL-2与Symbiodinium细胞的细胞表面结合。在这项研究中，我们测试了SLL-2对各种鞭毛藻的影响。将与生态相关的浓度添加到积极游泳共生sp的培养物中。 （C型）急剧减少了运动细胞的数量，而共生细胞开始转化为固定的球形形式，而细胞分裂不影响细胞分裂。非菌生鞭毛藻也对SLL-2做出了反应。体育症capenatum和prol中学麦芽胶在24小时内导致细胞死亡和细胞爆发后导致细胞死亡。因此，当前的结果强烈表明，凝集素介导的化学信号有助于洛氏链球菌和共生菌之间的稳定共生。这是在共生鞭毛鞭毛和珊瑚之间观察到的化学识别和生理调节的第一个证据。使用兔抗体对SLL-2抗体的相似成分的筛选表明，SLL-2似乎是针对Sinularia属的。