Structure of the mouse glucocorticoid receptor: rapid analysis by size-exclusion high-performance liquid chromatography.
Gel-exclusion high-performance liquid chromatography (HPLC) has been used to separate the untransformed from the transformed glucocorticoid receptor (GC-R) extracted from mouse AtT-20 cells. With 200 mM potassium phosphate as the eluent, an efficient separation of the forms of the GC-R is attained in 15-20 min. The untransformed cytosolic GC-R elutes from the column with a Stokes radius (Rs) of 8.2-8.6 nm, as do the molybdate-stabilized GC-R, the purified untransformed GC-R, and the cross-linked cytosolic GC-R. GC-R transformed in vitro by either ammonium sulfate precipitation, KCl treatment, or G-25 chromatography elutes with an Rs of 5.7-6 nm. Also, GC-R extracted from the nucleus with either 0.3 M KCl or 2 mM sodium tungstate, or purified by two cycles of DNA-cellulose chromatography, has an Rs of 5.5-6.3 nm. The data are identical either in the presence or in the absence of 20 mM Na2MoO4, suggesting that molybdate is not causing aggregation to produce a larger Rs value than that of the native receptor. Vertical tube rotor sucrose gradient ultracentrifugation of cytosol produces three forms of the GC-R: 9.1 S, 5.2 S, and 3.8 S. Sequential analysis of the GC-R forms by HPLC and vertical tube rotor ultracentrifugation and vice versa allows for the hydrodynamic determination of molecular weight within a very short time period (2-3 h total).(ABSTRACT TRUNCATED AT 250 WORDS)
LaPointe
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D000818:Animals; D002460:Cell Line; D002499:Centrifugation, Density Gradient / Q000379:methods; D002850:Chromatography, Gel / Q000379:methods; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D003600:Cytosol / Q000378:metabolism; D003907:Dexamethasone / Q000378:metabolism; D051379:Mice; D008970:Molecular Weight; D010911:Pituitary Neoplasms / Q000378:metabolism; D011487:Protein Conformation; D011965:Receptors, Glucocorticoid / Q000302:isolation & purification* / Q000378:metabolism
D011965:Receptors, Glucocorticoid; D003907:Dexamethasone