Degradation of Apolipoprotein B in Cultured Rat Hepatocytes Occurs in a Post-endoplasmic Reticulum Compartment (*)
Degradation of Apolipoprotein B in Cultured Rat Hepatocytes Occurs in a Post-endoplasmic Reticulum Compartment (*)
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培养的大鼠肝细胞中载脂蛋白 B 的降解发生在内质网后室 (*)
DOI：
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发表时间：
1995
影响因子：
4.8
通讯作者：
D. Brindley
中科院分区：
文献类型：
--
作者：
Chuen‐Neu Wang;T. Hobman;D. Brindley
在体外培养的大鼠肝细胞中研究了载脂蛋白B（apo B）的降解部位。布雷菲德菌素A加诺考达唑完全阻断载脂蛋白B的降解，表明参与后内质网（ER）室。莫能菌素抑制载脂蛋白B降解40%，这意味着后高尔基室可能参与了载脂蛋白B的降解。氯化铵或氯喹部分抑制apoB 100和apoB 48的降解，表明在溶酶体或酸性隔室如trans-Golgi或内体中有一些降解。（2S，3S）-trans-epoxysuccinyl-L-leucylamido-3-methylbutane ethyl ester（EST）可完全阻断apoB 100和apoB 48的降解，表明半胱氨酸蛋白酶参与apoB的降解。凝乳酶抑制素、亮抑酶素、胃酶抑制素、苯甲基磺酰氟和抑肽酶对apoB 48的降解没有显著影响。然而，亮抑酶肽和胃酶抑素使apoB 100的降解降低20- 30%。apoB 100和apoB 48在分离的高尔基体组分中发生降解，在重或轻ER中几乎没有降解。高尔基体组分中apoB的降解被EST和用10 nM地塞米松预孵育的肝细胞抑制。免疫荧光显微镜显示，载脂蛋白B积累在高尔基体区域后EST处理。它的结论是，大鼠肝细胞中的载脂蛋白B降解的主要部分发生在ER后隔室通过半胱氨酸蛋白酶，糖皮质激素调节的作用。
The site of apolipoprotein B (apoB) degradation was investigated in cultured rat hepatocytes. Brefeldin A plus nocodazole completely blocked apoB degradation suggesting the involvement of a post-endoplasmic reticulum (ER) compartment. Monensin inhibited apoB degradation by 40% implying that a post-Golgi compartment could be involved in degradation of apoB. Ammonium chloride or chloroquine inhibited partially the degradation of apoB100 and apoB48, indicating some degradation in lysosomes, or in an acidic compartment such as trans-Golgi or endosomes. The degradations of apoB100 and apoB48 were blocked completely by (2S,3S)-trans-epoxysuccinyl-L-leucylamido-3-methylbutane ethyl ester (EST) during a chase of 90 min demonstrating that a cysteine protease was responsible for apoB degradation. Chymostatin, leupeptin, pepstatin, phenylmethylsulfonyl fluoride, and aprotinin had no significant effect on the degradation of apoB48. However, leupeptin and pepstatin decreased the degradation of apoB100 by 20-30%. Degradation of apoB100 and apoB48 occurred in isolated Golgi fractions with little degradation in heavy or light ER. Degradation of apoB in Golgi fractions was inhibited by EST and by preincubating hepatocytes with 10 nM dexamethasone. Immunofluorescent microscopy revealed that apoB accumulated in the Golgi region after EST treatment. It is concluded that a major part of apoB degradation in rat hepatocytes occurs in a post-ER compartment via the action of a cysteine protease that is regulated by glucocorticoids.
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影响因子：
6.5
作者：
Robert L. Hamilton;A. Moorehouse;Richard J. Havel
通讯作者：
Robert L. Hamilton;A. Moorehouse;Richard J. Havel
影响因子：
56.9
作者：
CHEN, SH;HABIB, G;CHAN, L
通讯作者：
CHAN, L
完整肝细胞依次组装极低密度脂蛋白载脂蛋白、三酰甘油和磷酸甘油酯。
DOI：
--
发表时间：
1983
期刊：
The Journal of biological chemistry
影响因子：
--
作者：
Janero,DR;Lane,MD
通讯作者：
Lane,MD
载脂蛋白 B 暂停转移序列的分析。
DOI：
--
发表时间：
1993
期刊：
The Journal of biological chemistry
影响因子：
--
作者：
Chuck,SL;Lingappa,VR
通讯作者：
Lingappa,VR
胰岛素对大鼠肝细胞肝脏合成和载脂蛋白 B 分泌的调节。
DOI：
--
发表时间：
1990
期刊：
The Journal of biological chemistry
影响因子：
--
作者：
Sparks,JD;Sparks,CE
通讯作者：
Sparks,CE