Conditional modulation of membrane protein expression in cultured cells mediated by prion protein recognition of short phosphorothioate oligodeoxynucleotides
J Biol Chem. 2011 Mar 4;286(9):6911-7. Epub 2010 Dec 14.
|Type of Publication:||Journal Article|
ABSTRACT:We demonstrate that the levels of native as well as transfected prion protein (PrP) are lowered in various cell lines exposed to Phosphorothioate oligodeoxynucleotides (PS-DNA) and can be rapidly reverted to their normal amounts by removal of PS-DNA. This transient modulation was independent of the glycosylation state of PrP as all 3 PrP glycoforms were susceptible to PS-DNA treatment. Deletion of the N-terminal domain (aa 23-99), but not of other domains of PrP, abrogated its PS-DNA mediated down-regulation. PrP versions localized in the mitochondria, cytoplasm, or in the nucleus, were not modulated by PS-DNA, indicating that PrP surface exposure is required for executing this effect. Proteins that in their native forms were not responsive to PS-DNA, such as Thymocyte antigen 1 (Thy1), Doppel protein (Dpl), Green fluorescent protein (GFP) and Cyan fluorescent protein (CFP), became susceptible to PS-DNA-mediated down-regulation, following introduction of the N-terminus of PrP into their sequence. These observations demonstrate the essential role of the N-terminal domain of for promoting oligonucleotide-mediated reduction of the PrP level and suggest that transient treatment of cultured cells with PS-DNA may provide a general method for targeted modulation of the levels of desired surface proteins in a conditional and reversible manner.