A major phosphoprotein of the endoplasmic reticulum is protein disulfide isomerase.
One of the effects of ATP in the endoplasmic reticulum is to induce the phosphorylation of several proteins among which a 57-kDa protein (pp57) prevails in our labeling conditions. We provide evidence that pp57 is protein disulfide isomerase ( PDI), an abundant ubiquitous protein of the endoplasmic reticulum involved in various important cellular functions. This phosphorylation does not result from the activity of a microsomal protein kinase but from an autophosphorylation as described for other microsomal proteins such as chaperones. Phosphoamino acid analysis and cyanogen bromide cleavage indicate that the modification site lies on a threonine residue within the central region of the protein outside the thioredoxin-like domains. For the pure PDI, only the dimer is able to phosphorylate, while some experiments suggest that within the endoplasmic reticulum the phosphorylated form of PDI is mainly mobilized in larger size oligomers. Thus a possible role for this phosphorylation may be to modulate the association of PDI with its different partners.[1]References
- A major phosphoprotein of the endoplasmic reticulum is protein disulfide isomerase. Quéméneur, E., Guthapfel, R., Gueguen, P. J. Biol. Chem. (1994) [Pubmed]
Annotations and hyperlinks in this abstract are from individual authors of WikiGenes or automatically generated by the WikiGenes Data Mining Engine. The abstract is from MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.About WikiGenesOpen Access LicencePrivacy PolicyTerms of Useapsburg
