College of Life Sciences, Liaoning Normal University, Dalian 116029, China.
Immunol Lett. 2012 Apr 30;143(2):137-45. doi: 10.1016/j.imlet.2011.12.004. Epub 2012 Jan 21.
For the sea cucumber Apostichopus japonicus, a C-type lectin (AJCTL) was identified using rapid amplification of cDNA ends (RACE) PCR techniques. The full-length cDNA of AJCTL is composed of 710bp with a 618bp open reading frame (ORF) that encodes a polypeptide of 205 amino acids with a N-terminal signal peptide and a C-terminal C-type lectin domain (CTLD). The calculated molecular mass of the whole protein is 22.5kDa and its predicted isoelectric point is 5.59. AJCTL belongs to the group VII of regulatory proteins and it might function as a Ca(2+)-dependent monosaccharide binding lectin specifically and recognizing mannose-type ligands. In situ hybridization demonstrated that the expression of AJCTL was located in the body wall, longitudinal muscles, intestinum and respiratory tree. This became apparent especially in the cytoplasm of epidermal cells and granular haemocytes. Real-time PCR data suggested that AJCTL was mostly synthesized in the longitudinal muscles and intestinum and less pronounced in the respiratory tree and body wall of adults. After 12h stimulation by Vibrio harveyi, at increasing bacterial concentration gradient, the expression of AJCTL in sea cucumber increased as well. This indicated that CTL is related to an innate immune response.
利用快速扩增 cDNA 末端（RACE）PCR 技术，从刺参（Apostichopus japonicus）中鉴定出一种 C 型凝集素（AJCTL）。AJCTL 的全长 cDNA 由 710bp 组成，其中包含 618bp 的开放阅读框（ORF），编码 205 个氨基酸的多肽，其 N 端带有信号肽，C 端带有 C 型凝集素结构域（CTLD）。该蛋白的理论分子量为 22.5kDa，理论等电点为 5.59。AJCTL 属于调节蛋白的第 VII 组，可能作为一种 Ca(2+)-依赖性单糖结合凝集素，特异性识别甘露糖型配体。原位杂交表明，AJCTL 的表达定位于体壁、纵肌、肠和呼吸树。这在表皮细胞和颗粒血细胞的细胞质中表现得尤为明显。实时 PCR 数据表明，AJCTL 在纵肌和肠中合成较多，在呼吸树和体壁中合成较少。经哈维弧菌刺激 12 小时后，随着细菌浓度梯度的增加，刺参 AJCTL 的表达也随之增加。这表明 CTL 与先天免疫反应有关。
