Intracellular localization of the 90 kDA heat shock protein (HSP90alpha) determined by expression of a EGFP-HSP90alpha-fusion protein in unstressed and heat stressed 3T3 cells.
Heat shock protein 90 (Hsp90) is an abundant protein and essential for all eukaryotic cells. The expression of Hsp90 is further enhanced after exposure to stress factors, e.g. a heat shock. Many proteins interacting with Hsp90 as well as the various functions for Hsp90 have been described. In this study, an Hsp90alpha fusion protein along with the enhanced green fluorescence protein (EGFP) was expressed under the control of the human cytomegalovirus immediate early promoter. EGFP-Hsp90alpha was mainly localized in the cytoplasm, with only minor amounts inside the nuclei. No EGFP-Hsp90alpha could be detected inside the nucleoli. Following exposure to elevated temperatures, higher amounts of EGFP-Hsp90alpha are inside the nucleus, but not within the nucleoli. As the most remarkable finding under these conditions, an association of EGFP-Hsp90alpha with the nuclear membrane became visible.
Langer
Thomas
T
Institut für Biochemie und Biophysikalische Chemie der Johann Wolfgang Goethe-Universität Frankfurt am Main, Marie-Curie-Str. 9, 60439 Frankfurt am Main, Germany. t.langer@nmr.uni-frankfurt.de
Rosmus
Susann
S
Fasold
Hugo
H
D016475:3T3 Cells; D000818:Animals; D002466:Cell Nucleolus / Q000378:metabolism; D003593:Cytoplasm / Q000378:metabolism; D049452:Green Fluorescent Proteins; D018841:HSP90 Heat-Shock Proteins / Q000235:genetics* / Q000378:metabolism*; D018869:Heat-Shock Response / Q000502:physiology*; D007202:Indicators and Reagents / Q000378:metabolism; D008164:Luminescent Proteins / Q000235:genetics; D051379:Mice; D009685:Nuclear Envelope / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism
D018841:HSP90 Heat-Shock Proteins; D007202:Indicators and Reagents; D008164:Luminescent Proteins; D011993:Recombinant Fusion Proteins; D049452:Green Fluorescent Proteins