A novel cycle involving fatty acyl-coenzyme A regulates asialoglycoprotein receptor activity in permeable hepatocytes.
A novel cycle involving fatty acyl-coenzyme A regulates asialoglycoprotein receptor activity in permeable hepatocytes.
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涉及脂酰辅酶 A 的新循环调节可渗透性肝细胞中的脱唾液酸糖蛋白受体活性。
DOI：
10.1091/mbc.5.2.227
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发表时间：
1994
影响因子：
3.3
通讯作者：
Oka,JA
中科院分区：
文献类型：
--
作者：
Weigel,PH;Medh,JD;Oka,JA
通透性大鼠肝细胞中的去唾液酸糖蛋白受体 (ASGP-R) 在没有配体的情况下可能会失活。这种不依赖于细胞质的效应相对较慢（t1/2 大约 12 分钟），并且依赖于温度和 ATP。在这里，我们表明，在没有胞质溶胶的情况下，快速添加棕榈酰辅酶A (Pal-CoA) (t1/2 < 0.4 分钟) 并定量地重新激活失活的受体。在 37 摄氏度下，约 10-12 µM 游离 Pal-CoA 时，受体再激活达到最大一半。尽管使用了高得多的总浓度，但大部分添加的 Pal-CoA 是细胞相关的，而不是游离的。 Pal-CoA 的作用在足以结合所有游离单体脂肪酰基-CoA 的浓度下被牛血清白蛋白消除，表明胶束效应与重新激活 ASGP-R 的能力无关。此外，棕榈酰肉碱不能替代 Pal-CoA。最初的 ASGP-R 失活不受用 N-乙基马来酰亚胺处理细胞或 KCl 洗涤的影响，但会受到原钒酸钠或高 Ca2+ 水平的抑制。肉豆蔻酰辅酶A (C14) 也能够像 Pal-CoA 一样重新激活失活的 ASGP-R。链长为 C12（月桂酰）或 C18（甾酰）的脂肪酰辅酶 A 活性 < 50%。随后可以通过进一步添加 ATP 或 Pal-CoA 在几分钟内调节这些受体的配体结合活性，以分别实现额外轮次的 ASGP-R 失活或再激活。这些体外数据证明了一种新型脱唾液酸糖蛋白受体失活-再激活循环的发生，该循环可以在内吞作用和受体再循环过程中调节受体活性。
Asialoglycoprotein receptors (ASGP-Rs) in permeable rat hepatocytes can be inactivated in the absence of ligand. This cytosol-independent effect is relatively slow (t1/2 approximately 12 min) and is temperature and ATP dependent. Here we show that in the absence of cytosol, the addition of palmitoyl-CoA (Pal-CoA) rapidly (t1/2 < 0.4 min) and quantitatively reactivates the inactivated receptors. Receptor reactivation was half-maximal at approximately 10-12 microM free Pal-CoA at 37 degrees C. Although substantially higher total concentrations were used, much of the added Pal-CoA was cell associated and not free. The effects of Pal-CoA were eliminated by bovine serum albumin at concentrations sufficient to bind all free monomeric fatty acyl-CoA, suggesting that micellar effects are not responsible for the ability to reactivate ASGP-Rs. Also, palmitoyl-carnitine did not substitute for Pal-CoA. The initial ASGP-R inactivation is not affected by treating cells with N-ethylmaleimide or by a KCl wash but is inhibited by sodium orthovanadate or high Ca2+ levels. Myristoyl-CoA (C14) was also able to reactivate inactive ASGP-Rs about as well as Pal-CoA. Fatty acyl-CoAs with chain lengths of C12 (lauroyl) or C18 (steroyl) were < 50% as active. The ligand binding activity of these receptors can subsequently be modulated within minutes by the further addition of ATP or Pal-CoA to achieve additional rounds of ASGP-R inactivation or reactivation, respectively. These in vitro data demonstrate the occurrence of a novel asialoglycoprotein receptor inactivation-reactivation cycle that could regulate receptor activity during endocytosis and receptor recycling.
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大鼠肝脏过氧化物酶体中甘油脂前体的生物合成及其在内质网中转运和转化为磷脂酸盐。
DOI：
--
发表时间：
1992
期刊：
The Journal of biological chemistry
影响因子：
--
作者：
Das,AK;Horie,S;Hajra,AK
通讯作者：
Hajra,AK
影响因子：
13.6
作者：
E. Olson
通讯作者：
E. Olson
脂肪酸与培养的人体细胞中的转铁蛋白受体共价结合。
DOI：
--
发表时间：
1981
期刊：
The Journal of biological chemistry
影响因子：
--
作者：
Omary,MB;Trowbridge,IS
通讯作者：
Trowbridge,IS
CoA 和酰基 CoAs 对大鼠肝微粒体囊泡中 GTP 依赖性 Ca2 释放和囊泡融合的影响。
DOI：
10.1042/bj2890561
发表时间：
1993
期刊：
The Biochemical journal
影响因子：
--
作者：
J. G. Comerford;A. Dawson
通讯作者：
A. Dawson
脂肪酰辅酶A的物理性质。
影响因子：
4.8
作者：
P. Constantinides;J. Steim
通讯作者：
J. Steim