Genetic engineering of the glucocorticoid receptor by fusion with the herpes viral protein VP22 causes selective loss of transactivation.
The development of methods for engineering proteins with novel properties opens the way to manipulating intracellular processes in a therapeutically useful way. Glucocorticoids, acting via glucocorticoid receptors (GR), are potent anti-inflammatory agents, acting to oppose nuclear factor kappa B (NF kappa B) function. The herpes viral protein, VP22, has been reported to confer intercellular trafficking activity on 'cargo' proteins, potentially facilitating gene therapy with intracellular proteins. VP22GR, resulting from the addition of VP22 to the N terminal of GR, was equipotent with the wild-type GR in opposing NF kappa B p65-driven expression of an NF kappa B reporter gene. Surprisingly, VP22GR was incapable of inducing transactivation of positive glucocorticoid reporter genes (MMTV-luc and TAT3-luc). Furthermore, the VP22GR had powerful dominant negative activity on both endogenous and exogenous GR transactivation. VP22GR was cytoplasmic in quiescent cells, and after hormone addition underwent nuclear translocation to share the same distribution as the GR. The ability of the VP22GR to selectively confer and enhance glucocorticoid-dependent transrepression of NF kappa B may be of use therapeutically in e.g. transplant rejection, inflammatory arthritis or asthma.
Soden
J
J
Clinical Research Division II, Endocrine Sciences Research Group, Faculty of Medicine, Stopford Building, University of Manchester, Manchester M13 9PT, UK.
Stevens
A
A
Ray
D W
DW
D000818:Animals; D019556:COS Cells; D002460:Cell Line; D003593:Cytoplasm / Q000378:metabolism; D015870:Gene Expression; D005818:Genetic Engineering; D015316:Genetic Therapy; D006367:HeLa Cells; D006801:Humans; D016328:NF-kappa B / Q000235:genetics*; D011965:Receptors, Glucocorticoid / Q000235:genetics*; D011993:Recombinant Fusion Proteins / Q000378:metabolism*; D013601:T-Lymphocytes; D015533:Transcriptional Activation; D014162:Transfection; D015678:Viral Structural Proteins / Q000235:genetics*
D016328:NF-kappa B; D011965:Receptors, Glucocorticoid; D011993:Recombinant Fusion Proteins; D015678:Viral Structural Proteins; C073413:herpes simplex virus type 1 protein VP22