These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


PUBMED FOR HANDHELDS

Search MEDLINE/PubMed


  • Title: Epitope tagging of the human endoplasmic reticulum HSP70 protein, BiP, to facilitate analysis of BiP--substrate interactions.
    Author: Murray PJ, Watowich SS, Lodish HF, Young RA, Hilton DJ.
    Journal: Anal Biochem; 1995 Aug 10; 229(2):170-9. PubMed ID: 7485969.
    Abstract:
    We modified BiP, the resident endoplasmic reticulum (ER) heat shock protein 70, to contain an epitopetag sequence close to the C-terminus (BiP-tag); the epitope is derived from an influenza hemagglutinin (HA) subtype and is recognized by the monoclonal antibody 12CA5. This antibody both immunoprecipitates BiP-tag and detects it on Western blots. Using transient expression of cDNAs in COS cells, we studied the interaction of BiP-tag with several membrane proteins. Consistent with previous work on BiP, BiP-tag bound poorly and transiently to newly made wild-type influenza HA glycoprotein and strongly and irreversibly to an HA mutant that misfolds and is retained in the ER. Most newly made erythropoietin receptor (EPO-R) polypeptides are retained in the ER and degraded there; we show here that, in cotransfected COS cells, newly made EPO-R is bound to BiP-tag prior to its degradation. Thus, by several criteria the BiP-tag molecule is fully functional in binding newly made proteins. Because it can be immunoprecipitated by a readily available antibody, it offers several advantages to the study of protein folding in the ER and the role of chaperones in this process.
    [Abstract] [Full Text] [Related] [New Search]