MOLECULAR CHAPERONES INVOLVED IN PROTEIN-DEGRADATION IN THE ENDOPLASMIC-RETICULUM - QUANTITATIVE INTERACTION OF THE HEAT-SHOCK COGNATE PROTEIN BIP WITH PARTIALLY FOLDED IMMUNOGLOBULIN LIGHT-CHAINS THAT ARE DEGRADED IN THE ENDOPLASMIC-RETICULUM
MOLECULAR CHAPERONES INVOLVED IN PROTEIN-DEGRADATION IN THE ENDOPLASMIC-RETICULUM - QUANTITATIVE INTERACTION OF THE HEAT-SHOCK COGNATE PROTEIN BIP WITH PARTIALLY FOLDED IMMUNOGLOBULIN LIGHT-CHAINS THAT ARE DEGRADED IN THE ENDOPLASMIC-RETICULUM
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DOI：
10.1073/pnas.92.5.1764
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发表时间：
1995-02-28
影响因子：
11.1
通讯作者：
HAAS, IG
中科院分区：
文献类型：
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作者：
KNITTLER, MR;DIRKS, S;HAAS, IG
在没有免疫球蛋白重链表达的情况下，一些免疫球蛋白轻链(L)被保留并在细胞内降解。我们研究了两条不同半衰期(50min和3-4小时)的小鼠L非分泌链的命运，结果表明这两条非分泌性L链都以部分氧化分子的形式与BiP定量结合。BIP中L链的降解动力学与L链的解离动力学相吻合，表明这两个过程在功能上是相关的。L链的降解不依赖于囊泡的转运，表明这些可溶性蛋白是在内质网(ER)中降解的。相反，分泌的L链只与BiP瞬时相互作用，被完全氧化，即使人工保留在内质网中也不被降解，我们的数据支持这样的模型，即通过BiP相互作用，ER降解机制有可能区分部分折叠和完全折叠的分子。
In the absence of immunoglobulin heavy-chain expression, some immunoglobulin light (L) chains are retained and degraded within the cell. We investigated the fate of two different nonsecreted murine L chains which exhibit different half-lives (50 min and 3-4 hr), Our results demonstrate that both nonsecreted L chains are quantitatively bound to BiP as partially oxidized molecules. The kinetics of L-chain degradation coincided with those of L-chain dissociation from BiP, which suggests that these two processes are functionally related. L-chain degradation does not depend on vesicular transport, indicating that these soluble proteins are degraded in the endoplasmic reticulum (ER). In contrast, secreted L chains, which interact only transiently with BiP, are completely oxidized and are not degraded even when they are artificially retained in the ER, Our data support the model that, by means of BiP interaction, the ER degradation mechanism has the potential to discriminate between partially and completely folded molecules.