共查询到18条相似文献,搜索用时 100 毫秒
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作为维持哺乳动物生命活动重要的"生物工厂",乳腺利用从流经血液中摄取的氨基酸等营养物质为底物合成乳蛋白。研究证实,氨基酸还可作为一种信号因子,通过乳腺内多种信号级联传导通路,调控乳蛋白基因的转录及翻译过程,从而影响乳腺中乳蛋白的合成。酪氨酸蛋白激酶-信号转导子和转录激活子(JAK-STAT)信号通路和哺乳动物雷帕霉素靶蛋白(m TOR)信号通路是乳蛋白基因转录和翻译过程中的主要调控路径。本文综述了乳腺JAKSTAT和m TOR信号通路的分子机制及氨基酸通过这些通路调控乳蛋白合成的研究进展,旨在进一步阐明氨基酸调控乳蛋白合成的作用机理。 相似文献
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氨基酸不仅是蛋白质和其他含氮化合物合成的重要前体,还参与体内主要代谢途径的调控。当氨基酸不足时,机体内多种机制参与调节体内平衡,包括快速停止蛋白质合成、增加氨基酸合成和转运,以及加强自噬作用。越来越多的学者证明氨基酸可作为信号分子参与细胞内信号传导过程,可以调节其他营养素如脂肪和能量的代谢,最终导致机体整体代谢的改变。本文主要综述细胞内氨基酸的营养感知与应答机制,涉及氨基酸应答(AAR)和雷帕霉素靶蛋白(TOR)2条信号转导通路,并探讨这2条信号通路对下游营养素代谢途径的调节。 相似文献
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哺乳动物雷帕霉素靶蛋白(mTOR)是一种非典型丝氨酸/苏氨酸蛋白激酶,是mTOR信号通路的重要分子。mTOR可整合氨基酸、能量和激素等多种细胞外信号,参与基因转录、蛋白质翻译等生物过程。本文总结了mTOR信号通路特点及信号途径,重点介绍了营养素(氨基酸、能量底物)和激素(主要是胰岛素)在乳蛋白合成过程中对mTOR信号通路的调节作用。 相似文献
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高迁移率族蛋白B1(HMGB1)在核外表达时既是炎症早期的启动者,又是炎症晚期的促进者,是内毒素血症致机体死亡病理过程的中间物质。内毒素和多种前炎症因子如TNF-α、IL-1等刺激单核/巨噬细胞后,可诱导HMGB1的释放。JAK/STAT信号传导通路可以上调HMGB1蛋白的表达,MAPKs信号传导通路介导了HMGB1的核浆转移及胞外释放过程,而胞外的HMGB1可通过NF-κB信号传导通路诱导靶细胞产生大量的炎性细胞因子。本文就HMGB1的传导通路、靶细胞上的信号受体及其在致炎细胞因子网络中的作用进行综述。 相似文献
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不同信号转导通路间的彼此协调保证了机体的正常运行。在众多的信号通路中,转化生长因子(TGF)β1/Smads信号传导通路越来越受到学者们的关注,已经成为分子生物学和细胞生物学研究的一大热点。已有研究证实,TGF-β1/Smads信号传导通路是调控卵泡发育的重要途径。本文就TGF-β1/Smads信号传导通路与哺乳动物卵巢卵泡的发育进行综述,分别从TGF-β受体、Smads蛋白、骨形态发生蛋白(BMP)、血小板反应蛋白1(THB-S1)、S期激酶相关蛋白1(SKP1)和其他调节机制阐述TGF-β1/Smads信号传导通路在哺乳动物卵巢发育中的调控作用及其机制,旨在引起人们对TGF-β1/Smads调控卵巢发育的关注,并为卵巢发育过程中某些疾病的治疗提供一些参考。 相似文献
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《畜牧与生物技术杂志(英文版)》2017,(3)
It is widely known that branched chain amino acids(BCAA) are not only elementary components for building muscle tissue but also participate in increasing protein synthesis in animals and humans. BCAA(isoleucine, leucine and valine) regulate many key signaling pathways, the most classic of which is the activation of the m TOR signaling pathway. This signaling pathway connects many diverse physiological and metabolic roles. Recent years have witnessed many striking developments in determining the novel functions of BCAA including:(1) Insufficient or excessive levels of BCAA in the diet enhances lipolysis.(2) BCAA, especially isoleucine, play a major role in enhancing glucose consumption and utilization by up-regulating intestinal and muscular glucose transporters.(3)Supplementation of leucine in the diet enhances meat quality in finishing pigs.(4) BCAA are beneficial for mammary health, milk quality and embryo growth.(5) BCAA enhance intestinal development, intestinal amino acid transportation and mucin production.(6) BCAA participate in up-regulating innate and adaptive immune responses.In addition, abnormally elevated BCAA levels in the blood(decreased BCAA catabolism) are a good biomarker for the early detection of obesity, diabetes and other metabolic diseases. This review will provide some insights into these novel metabolic and physiological functions of BCAA. 相似文献
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Fish have limited ability in endogenous biosynthesis of arginine. Arginine is an indispensable amino acid for fish, and the arginine requirement varies with fish species and fish size. Recent studies on fish have demonstrated that arginine influences nutrient metabolism, stimulates insulin release, is involved in nonspecific immune responses and antioxidant responses, and elevates disease resistance. Specifically, arginine can regulate energy homeostasis via modulating the adenosine 5'-monophosphate (AMP)-activated protein kinase (AMPK) pathway, and also regulate protein synthesis via activating the target of rapamycin (TOR) signaling pathway. The present article reviews pertinent knowledge of arginine in fish, including dietary quantitative requirements, endogenous anabolism and catabolism, regulation of the endocrine and metabolic systems, and immune-regulatory functions under pathogenic challenge. Our findings showed that further data about the distribution of arginine after intake into specific cells, its sub-cellular sensor to initiate downstream signaling pathways, and its effects on fish mucosal immunity, especially the adaptive immune response against pathogenic infection in different species, are urgently needed. 相似文献
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氨基酸转运载体(AAT)是一类介导氨基酸从细胞外转运到细胞内的重要蛋白,也是一类能介导氨基酸相关的信号通路的重要营养物质感受分子,在机体的生长代谢、营养健康等方面具有重要作用。动物机体中存在多种类型的AAT,它们能感知机体内相关氨基酸水平的变化,介导细胞氨基酸感知信号通路——哺乳动物雷帕霉素靶蛋白复合体1(mTORC1)和一般性调控阻遏蛋白激酶2(GCN2)的激活,从而引起通路下游发挥作用。在不同组织细胞中,发挥主导作用的AAT存在差异,表明AAT具有组织特异性,同时,AAT也受多种因素的影响,比如动物机体本身、营养物质水平、激素水平等。作者主要从AAT的类型及转运机制、介导营养信号启动及对mTORC1通路和GCN通路的影响、在不同组织中的作用及AAT表达的调控4个方面进行综述,从宏观方面介绍了AAT,旨在为AAT的研究提供一些参考。 相似文献
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Duchêne S Métayer S Audouin E Bigot K Dupont J Tesseraud S 《Domestic animal endocrinology》2008,34(1):1-13
p70 S6 kinase (p70S6K) is a key enzyme involved in the control of protein synthesis. We have previously shown that this kinase is insulin sensitive in chicken muscle despite a relative insulin resistance in the early steps of insulin receptor signaling in this tissue, particularly with no change in tyrosine phosphorylation of the insulin receptor substrate 1 (IRS1). The aim of the present study is to further study the p70S6K pathway in chicken muscle. By analyzing in silico several kinases involved in the protein kinase B (PKB also called AKT)/target of rapamycin (TOR)/p70S6K pathway in the chicken, we showed that the amino acid sequence of the proteins exhibited a very high identity with their homologs in mammalian species and Drosophila. We investigated the regulation of these kinases in vivo or in vitro. Refeeding and insulin treatment significantly (P<0.05) increased the phosphorylation and/or activity of kinases upstream of p70S6K such as AKT and TOR. Similarly, refeeding and insulin increased the phosphorylation of p70S6K on key residues (i.e. T389, T229 and T421/S424) and the phosphorylation of a p70S6K downstream target, the ribosomal protein S6 (by 3-10-fold, P<0.05). Interestingly, we also showed an increase in the phosphorylation level of IRS1 on S632/S635, sites involved in insulin resistance. In conclusion, the AKT/TOR/p70S6K pathway is activated by refeeding and insulin injection, which might negatively regulate IRS1 tyrosine phosphorylation. These results indicate some particularities of the insulin signaling in chicken muscle and suggest the involvement of p70S6K in these features. 相似文献
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LI Ying XIANG Ai-li ZHENG Bai-qin ZHOU Xiao-qiao QIAO Jia-yun LIU Jing-xi WANG Wen-jie 《中国畜牧兽医》2016,43(7):1774-1779
Milk proteins have great nutritional value,rich contain and balanced profile of amino acid,which provide nearly all the essential amino acids for the human body.However more than 90% of milk proteins are synthesed by the amino acids in the mammary gland.Furthermore,the amino acid is not only funcion as the substrates of milk protein synthesis,but also as the signaling molecules to regulate milk protein sysnthesis through mammalian target of rapamycin (mTOR) signaling pathways.It is essential to further study milk protein synthesis regulated by amino acids in the mammary gland and the molecular mechanism in dairy cows.The paper reviewed the supply of amino acids,metabolism of amino acids by mammary gland,factors affecting amino acid utilization and signal pathway for amino acid regulation in milk protein synthesis. 相似文献
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乳蛋白中含有大量人体所需的必需氨基酸,其组成平衡、含量丰富,是一种具有极高营养价值的蛋白质,而乳中 90%以上的蛋白质是乳腺利用氨基酸从头合成的,因此氨基酸对奶牛乳蛋白合成发挥着重要的作用。此外,氨基酸不仅是合成乳蛋白不可或缺的前体物质,而且还是重要的信号调控因子,通过哺乳动物雷帕霉素靶蛋白(mTOR) 信号通路调控乳蛋白的合成。基于此,作者就影响奶牛乳腺氨基酸供应、摄取、利用的因素及氨基酸的信号传导作用的研究进展进行综述,以期为提高乳蛋白的合成提供一定的理论基础。 相似文献
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The intestine is the primary organ responsible for digestion and absorption of nutrients and is frequently subjected to external environmental stimulations leading to the development of inflammatory bowel disease (IBD), which can cause serious harm to intestinal health in animals. Dietary amino acids play important roles in promoting intestinal development and maintaining intestinal health and exert diverse effects through multiple signaling pathways on the prevention and treatment of IBD, including affecting the physiological activities of intestinal epithelial cells, improving intestinal barrier function, reducing intestinal oxidative damage, regulating the production of inflammatory cytokines, and promoting the expression of endogenous antimicrobial peptides, and involved in main signaling pathways including AMP-activated kinase (AMPK), mammalian target of rapamycin (mTOR), mitogen-activated protein kinase (MAPK), Toll-like receptors (TLRs), nucleotide binding oligomerization domain (NOD)/nuclear factor kappa-B (NF-κB). In this review, basic characteristics of IBD, effects and involved signaling pathways of the amino acids on IBD, and effects and applications of amino acids in maintaining intestinal health in livestock and poultry production were reviewed, so as to provide effective clues and strategies for dietary nutrients in the prevention and treatment of IBD. 相似文献