Growth hormone (GH) participates in many physiological processes through the activation of its membrane-anchored receptor (GHR) in vertebrates. Because of its pivotal role in regulating growth and development, a large number of studies examining GH-GHR have been conducted in mammals, birds and fish. However, whether a functional GH-GHR pair exists in the Chinese soft-shelled turtle (st-) has not been previously studied. Here, the full-length cDNA encoding GH was cloned from Chinese soft-shelled turtle () pituitary. The results revealed that it consisted of 784 bp and encoded a precursor of 217 amino acids. Furthermore, recombinant stGH was prepared and purified from () strain BL21. Using the 5×STAT5-Luciferase reporter system, we found that stGHR expressed in human hepatocellular carcinoma cells could be activated in a dose-dependent manner by recombinant stGH, thereby triggering the intracellular JAK2-STAT5 signaling pathway, suggesting stGH is a functional ligand for stGHR. Quantitative real-time PCR revealed that mRNA was predominantly and abundantly expressed in pituitary, while exhibited ubiquitous expression in all tissues examined, including pituitary and liver. Collectively, our data indicate a conserved GH-GHR pair might function in reptiles including Chinese soft-shelled turtle, as that in mammals, birds and fishes.

中文翻译：

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中华鳖生长激素（GH）特征：分子鉴定、GH受体激活能力和组织分布


生长激素（GH）通过激活脊椎动物的膜锚定受体（GHR）参与许多生理过程。由于 GH-GHR 在调节生长和发育方面发挥着关键作用，因此在哺乳动物、鸟类和鱼类中进行了大量检查 GH-GHR 的研究。然而，此前尚未研究过中华鳖（st-）中是否存在功能性 GH-GHR 对。本研究从中华鳖垂体中克隆了编码GH的全长cDNA。结果显示，它由784 bp组成，编码217个氨基酸的前体。此外，从()菌株BL21中制备并纯化了重组stGH。利用5×STAT5-Luciferase报告系统，我们发现重组stGH可以以剂量依赖的方式激活人肝癌细胞中表达的stGHR，从而触发细胞内JAK2-STAT5信号通路，这表明stGH是一种功能性配体。 stGHR。定量实时 PCR 显示 mRNA 主要且大量地在垂体中表达，同时在所有检查的组织（包括垂体和肝脏）中都表现出普遍的表达。总的来说，我们的数据表明，保守的 GH-GHR 对可能在包括中华鳖在内的爬行动物中发挥作用，就像在哺乳动物、鸟类和鱼类中一样。