کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1931311 | 1050548 | 2010 | 6 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: Depletion of the cellular levels of Bag-1 proteins attenuates phorbol ester-induced downregulation of IκBα and nuclear accumulation of NF-κB Depletion of the cellular levels of Bag-1 proteins attenuates phorbol ester-induced downregulation of IκBα and nuclear accumulation of NF-κB](/preview/png/1931311.png)
Bag-1 consists in humans of four isoforms generated from the same RNA by alternative translation. Overexpression of single Bag-1 isoforms has identified Bag-1 as a negative regulator of action of many proteins including the glucocorticoid receptor (GR). Here we have analysed the ability of Bag-1 to regulate the transrepression function of the GR. Silencing Bag-1 expression only marginally affects the transrepression action of the GR but decreased the action of the transcription factor NF-κB. Furthermore phosphorylation and degradation of the inhibitor protein IκBα and nuclear accumulation of p65 and p50 NF-κB proteins in response to phorbol ester was attenuated following Bag-1 depletion in HeLa cells. Reconstitution of Bag-1 in depleted cells partially restored IκBα and NF-κB activation. Knock-down of Bag-1 expression also did not significantly alter GR-mediated transactivation but affected the basal transcription of some of the target genes. Thus Bag-1 proteins function as regulators of the action of selective transcription factors.
Research highlights
► Bag-1 depletion only marginally affects the action of the glucocorticoid receptor but strongly regulates the activity of NF-κB.
► Bag-1 depletion attenuates phosphorylation and degradation of IκBα and nuclear accumulation of NF-κB p65 and p50.
► Bag-1 interacts with IκBα and partially restores IκBα and NF-κB activation in Bag-1 depleted cells.
Journal: Biochemical and Biophysical Research Communications - Volume 401, Issue 3, 22 October 2010, Pages 406–411