Internalization and degradation of human alpha-A interferon bound to bovine MDBK cells: regulation of the decay and resynthesis of receptors.
Internalization and degradation of human alpha-A interferon bound to bovine MDBK cells: regulation of the decay and resynthesis of receptors.
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人α-A干扰素与牛MDBK细胞结合的内化和降解：受体衰变和再合成的调节。
DOI：
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发表时间：
1983
期刊：
影响因子：
--
通讯作者：
C. Baglioni
中科院分区：
文献类型：
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作者：
A. Branca;S. D'Alessandro;C. Baglioni
研究了125 I标记的人干扰素α-A（HuIFN-α A）与牛MDBK细胞受体的结合。在37 ℃下结合的125 I-干扰素比在0 ℃下结合的125 I-干扰素多4倍。为了确定细胞结合的IFN是否被内化，用稀释的乙酸处理细胞，这是一种已知的去除与细胞表面结合的多肽的方法。通过这种处理，约80%的在0 ℃下结合的IFN从细胞中解离，而在37 ℃下孵育2小时后，仅45%的结合的IFN被解离。接着在两个温度下检测在新鲜培养基中洗涤和孵育的细胞释放的细胞结合的125 I-干扰素。在0 ℃下，在2小时内，高达50%的细胞结合的IFN被释放到培养基中，而在37 ℃下，细胞结合的放射性在几个小时内作为酸溶性降解产物缓慢释放。因此，干扰素被37 ℃孵育的MDBK细胞内化和降解，但不被0 ℃孵育的细胞内化和降解。在37摄氏度的结合力增加可能是由IFN/受体复合物的内化和受体再循环到细胞表面来解释的。然而，这种再循环是有限的，因为用未标记的IFN孵育MDBK细胞导致可用受体的快速减少或下调。通过添加蛋白质和RNA合成的抑制剂来防止结合活性的恢复，这表明需要从头合成受体。在放线菌酮存在下，IFN受体的半衰期约为3小时。（250字处删节）
The binding of 125I-labeled human interferon alpha-A (HuIFN-alpha A) to receptors of bovine MDBK cells was investigated. About 4-fold more 125I-interferon was bound at 37 degrees C than at 0 degrees C. To establish whether the cell-bound IFN was internalized, the cells were treated with diluted acetic acid, a procedure known to remove polypeptides bound to the cell surface. About 80% of the IFN bound at 0 degrees C was dissociated from the cells by this treatment, whereas only 45% of that bound after a 2 h incubation at 37 degrees C was dissociated. Release of cell-bound 125I-interferon by cells washed and incubated in fresh medium was next examined at the two temperatures. At 0 degrees C, up to 50% of cell-bound IFN was released into the medium over a 2 h period, whereas at 37 degrees C the cell-bound radioactivity was slowly released over several hours as acid-soluble degradation products. Interferon was therefore internalized and degraded by MDBK cells incubated at 37 degrees C, but not by cells incubated at 0 degrees C. The increased binding at 37 degrees C could possibly be explained by the internalization of IFN/receptor complexes and by the recycling of the receptors to the cell surface. This recycling was limited, however, since incubation of MDBK cells with unlabeled IFN led to a rapid decrease or down regulation of available receptors. Recovery of binding activity was prevented by the addition of inhibitors of protein and RNA synthesis, suggesting that de novo synthesis of receptors was required. The half-life of the IFN receptor in the presence of cycloheximide was about 3 h.(ABSTRACT TRUNCATED AT 250 WORDS)
配体诱导肝细胞胰岛素受体水平下调的机制。
DOI：
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发表时间：
1981
期刊：
The Journal of biological chemistry
影响因子：
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作者：
Krupp,M;Lane,MD
通讯作者：
Lane,MD
DOI：
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发表时间：
1982
期刊：
The Journal of biological chemistry
影响因子：
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作者：
Branca,AA;Baglioni,C
通讯作者：
Baglioni,C
干扰素与细胞受体的相互作用。
DOI：
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发表时间：
1982
期刊：
The Journal of biological chemistry
影响因子：
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作者：
Branca,AA;Faltynek,CR;D'Alessandro,SB;Baglioni,C
通讯作者：
Baglioni,C