It is widely accepted that body weight and adipose mass are tightly regulated by homeostatic mechanisms, in which leptin plays a critical role through hypothalamic pathways, and obesity is a result of homeostatic diso...It is widely accepted that body weight and adipose mass are tightly regulated by homeostatic mechanisms, in which leptin plays a critical role through hypothalamic pathways, and obesity is a result of homeostatic disorder. However, in C57BL/6J mice, we found that Rcan2 increases food intake and plays an important role in the develop- ment of age- and diet-induced obesity through a leptin-independent mechanism. RCAN2 was initially identified as a thyroid hormone （T3）-responsive gene in human fibroblasts. Expression of RCAN2 is regulated by T3 through the PI3K-Akt/PKB-mTOR-Rps6kbl signaling pathway. Intriguingly, both Rcan2-/- and Rps6kb1-/- mutations were re- ported to result in lean phenotypes in mice. In this study we compared the effects of these two mutations on growth and body weight in C57BL/6J mice. We observed reduced body weight and lower fat mass in both Rcan2-/- and Rps6kb1-/- mice compared to the wild-type mice, and we reported other differences unique to either the Rcan2-/- or Rps6kb1-/- mice. Firstly, loss of Rcan2 does not directly alter body length; however, Rcan2-/- mice exhibit reduced food intake. In contrast, Rps6kb1-/- mice exhibit abnormal embryonic development, which leads to smaller body size and reduced food intake in adulthood. Secondly, when fed a normal chow diet, Rcan2-/- mice weigh significantly more than Rps6kb1-/- mice, but both Rcan2-/- and Rps6kbl-/- mice develop similar amounts of epididymal fat. On a high-fat diet, Rcan2-/- mice gain body weight and fat mass at slower rates than Rps6kb1-/- mice. Finally, using the double-knockout mice （Rcan2-/- Rps6kb1-/-）, we demonstrate that concurrent loss of Rcan2and Rps6kbl has an additive effect on body weight reduction in C57BL/6J mice. Our data suggest that Rcan2 and Rps6kbl mutations both affect growth and body weight of mice, though likely through different mechanisms.展开更多
核糖体蛋白S6激酶β1(Ribosomal protein S6 kinaseβ1,RPS6KB1)是一个有价值的肝癌诊断和预后标志物,也是一个潜在的基因治疗分子靶点,但其致癌机制和预后价值仍未完全阐明。为了全面认识RPS6KB1,本文使用生物信息学手段,对RPS6KB1蛋...核糖体蛋白S6激酶β1(Ribosomal protein S6 kinaseβ1,RPS6KB1)是一个有价值的肝癌诊断和预后标志物,也是一个潜在的基因治疗分子靶点,但其致癌机制和预后价值仍未完全阐明。为了全面认识RPS6KB1,本文使用生物信息学手段,对RPS6KB1蛋白的序列同源性、组织表达、亚细胞定位、理化性质、空间结构及蛋白质相互作用网络进行分析。结果表明人RPS6KB1基因编码525个氨基酸组成的多肽,在进化过程中高度保守,属于PKc_like超家族,是酸性不稳定的亲水蛋白,无信号肽和跨膜区域。该蛋白定位于细胞核的可能性最大,主要二级结构为随机卷曲,存在磷酸化、乙酰化和泛素化位点。与RPS6KB1相互作用的蛋白主要是m TOR信号途径相关蛋白、PI3K信号途径相关蛋白、蛋白质合成相关蛋白以及调控胰岛素水平相关蛋白。本文结果为进一步研究RPS6KB1的功能及致癌机制提供一定的参考。展开更多
基金Project supported by the National Natural Science Foundation of China(Nos.31140091 and 31371495)Shandong Natural Science Foundation(No.ZR2013CM040),China
文摘It is widely accepted that body weight and adipose mass are tightly regulated by homeostatic mechanisms, in which leptin plays a critical role through hypothalamic pathways, and obesity is a result of homeostatic disorder. However, in C57BL/6J mice, we found that Rcan2 increases food intake and plays an important role in the develop- ment of age- and diet-induced obesity through a leptin-independent mechanism. RCAN2 was initially identified as a thyroid hormone （T3）-responsive gene in human fibroblasts. Expression of RCAN2 is regulated by T3 through the PI3K-Akt/PKB-mTOR-Rps6kbl signaling pathway. Intriguingly, both Rcan2-/- and Rps6kb1-/- mutations were re- ported to result in lean phenotypes in mice. In this study we compared the effects of these two mutations on growth and body weight in C57BL/6J mice. We observed reduced body weight and lower fat mass in both Rcan2-/- and Rps6kb1-/- mice compared to the wild-type mice, and we reported other differences unique to either the Rcan2-/- or Rps6kb1-/- mice. Firstly, loss of Rcan2 does not directly alter body length; however, Rcan2-/- mice exhibit reduced food intake. In contrast, Rps6kb1-/- mice exhibit abnormal embryonic development, which leads to smaller body size and reduced food intake in adulthood. Secondly, when fed a normal chow diet, Rcan2-/- mice weigh significantly more than Rps6kb1-/- mice, but both Rcan2-/- and Rps6kbl-/- mice develop similar amounts of epididymal fat. On a high-fat diet, Rcan2-/- mice gain body weight and fat mass at slower rates than Rps6kb1-/- mice. Finally, using the double-knockout mice （Rcan2-/- Rps6kb1-/-）, we demonstrate that concurrent loss of Rcan2and Rps6kbl has an additive effect on body weight reduction in C57BL/6J mice. Our data suggest that Rcan2 and Rps6kbl mutations both affect growth and body weight of mice, though likely through different mechanisms.
文摘核糖体蛋白S6激酶β1(Ribosomal protein S6 kinaseβ1,RPS6KB1)是一个有价值的肝癌诊断和预后标志物,也是一个潜在的基因治疗分子靶点,但其致癌机制和预后价值仍未完全阐明。为了全面认识RPS6KB1,本文使用生物信息学手段,对RPS6KB1蛋白的序列同源性、组织表达、亚细胞定位、理化性质、空间结构及蛋白质相互作用网络进行分析。结果表明人RPS6KB1基因编码525个氨基酸组成的多肽,在进化过程中高度保守,属于PKc_like超家族,是酸性不稳定的亲水蛋白,无信号肽和跨膜区域。该蛋白定位于细胞核的可能性最大,主要二级结构为随机卷曲,存在磷酸化、乙酰化和泛素化位点。与RPS6KB1相互作用的蛋白主要是m TOR信号途径相关蛋白、PI3K信号途径相关蛋白、蛋白质合成相关蛋白以及调控胰岛素水平相关蛋白。本文结果为进一步研究RPS6KB1的功能及致癌机制提供一定的参考。
