A colony of cells is exposed to high-dose cortisol in an experimental setting. Which of the following intracellular substance is most likely to increase immediately after the exposure?
A. cAMP
B. IP3
C. Unbound hsp 90
D. Activated Ras
E. Phosporylated JAK
F. mRNA
Imam, Shiney and others, where are you?
Good job Imam.
Receptor proteins are either extracellular or intracellular ( in the cytoplasm or nucleus). The majority of recept are extracellular, with steroid hormone receptors the intracellular exception. When inactive, they are bound to the heat shock Protein 90 (hsp 90) and hsp 56. These heat shock proteins are released when the receptor binds the steroid hormone, and the receptor-hormone complex is the transported into the nucleus for gene transcription.
Addon:
The steroid(cortisol) is present in the blood bound to the corticosteroid-binding globulin(CBG) but enter the cell as free molecule. The intracellular receptor is bound to Hsp90, when the cortisol bind to it receptor, Hsp90 is released and that is the reason Hsp90 increased in the cytoplasm.
Yes Okt3. It could be Hsp 56 too.
Thanks, i did not know about the Hsp56, read something in UW but can not recall
Good qs