Differential expression of Hsp90 isoforms in geldanamycin-treated 9L cells.
In mammals, two major Hsp90 isoforms (Hsp90alpha and Hsp90beta) have been identified and found to be highly conserved among different species. However, the expression control of Hsp90 isoforms at both transcriptional and translational levels is largely unknown. Herein, we quantitatively investigate the changes in the total mRNA and inductive protein levels of Hsp90alpha and Hsp90beta in rat gliosarcoma cells treated with geldanamycin (GA). The stability of mRNA and protein was estimated. The translational efficiency of Hsp90 isoforms was measured employing in vitro translation techniques. It was found that Hsp90alpha was more inducible than Hsp90beta after GA treatment, whereas the hsp90alpha mRNA level was lower than that of hsp90beta. In addition, higher translational efficiency of hsp90alpha mRNA was observed, suggesting that translational control played an important role. Taken together, our results indicate that differential expression between Hsp90alpha and Hsp90beta is a consequence of both distinct mRNA profiles and differential translation processes.
Chang
Yuo-Sheng
YS
Institute of Biotechnology, Department of Life Science, National Tsing Hua University, Hsinchu, Taiwan 30013, ROC.
Lo
Chi-Wei
CW
Sun
Fang-Chun
FC
Chang
Margaret Dah-Tsyr
MD
Lai
Yiu-Kay
YK
D000818:Animals; D016227:Benzoquinones; D015870:Gene Expression / Q000187:drug effects; D018841:HSP90 Heat-Shock Proteins / Q000032:analysis / Q000235:genetics* / Q000378:metabolism*; D007700:Kinetics; D047029:Lactams, Macrocyclic; D009457:Neuroglia / Q000187:drug effects / Q000378:metabolism*; D014176:Protein Biosynthesis / Q000235:genetics; D020033:Protein Isoforms / Q000235:genetics; D011809:Quinones / Q000494:pharmacology; D012333:RNA, Messenger / Q000032:analysis / Q000378:metabolism; D051381:Rats
D016227:Benzoquinones; D018841:HSP90 Heat-Shock Proteins; D047029:Lactams, Macrocyclic; D020033:Protein Isoforms; D011809:Quinones; D012333:RNA, Messenger; C001277:geldanamycin