Gething M J
Department of Biochemistry and Molecular Biology, University of Melbourne, Parkville, Victoria, Australia.
Semin Cell Dev Biol. 1999 Oct;10(5):465-72. doi: 10.1006/scdb.1999.0318.
BiP, an HSP70 molecular chaperone located in the lumen of the endoplasmic reticulum (ER), binds newly-synthesized proteins as they are translocated into the ER and maintains them in a state competent for subsequent folding and oligomerization. BiP is also an essential component of the translocation machinery, as well as playing a role in retrograde transport across the ER membrane of aberrant proteins destined for degradation by the proteasome. BiP is an abundant protein under all growth conditions, but its synthesis is markedly induced under conditions that lead to the accumulation of unfolded polypeptides in the ER. This attribute provides a marker for disease states that result from misfolding of secretory and transmembrane proteins.
BiP是一种位于内质网（ER）腔中的热休克蛋白70（HSP70）分子伴侣，它在新合成的蛋白质转运到内质网时与之结合，并将它们维持在一种能够进行后续折叠和寡聚化的状态。BiP也是转运机制的重要组成部分，并且在异常蛋白质通过内质网膜进行逆行转运中发挥作用，这些异常蛋白质将被蛋白酶体降解。在所有生长条件下，BiP都是一种丰富的蛋白质，但其合成在导致内质网中未折叠多肽积累的条件下会显著诱导。这一特性为分泌蛋白和跨膜蛋白错误折叠导致的疾病状态提供了一个标志物。
