PKA controls a level of topoisomerase I mRNA in mouse L5178Y lymphoma cells treated with db-cAMP.
The level of topoisomerase I mRNA was measured in cells of two mouse lymphoma (LY) sublines treated with db-cAMP. A transient increase of the level was observed to be of about 60% of the basic level and to have maximum after the 3 h treatment of LY-S cells. The increase in LY-R subline was two-fold lower. The activity of PKA in a cytosol fraction of LY-S cells was 1.75 times higher than that in LY-R cells. The activity of PKA in membranes and nuclear fraction did not differ significantly in both cell types. When the activity of PKA in LY-S cells was inhibited with H8, no increase of the level of topoisomerase I mRNA was observed upon db-cAMP treatment of cells. We suggest that the activity of PKA in the cytosol controls the expression of topoisomerase I gene in LY cells at high concentration of cAMP.
Czerwinski
R M
RM
Institute of Biochemistry, Warsaw University, Poland.
Nieznanski
K
K
Sochanowicz
B
B
Staron
K
K
D000818:Animals; D003994:Bucladesine / Q000494:pharmacology*; D002451:Cell Compartmentation; D017868:Cyclic AMP-Dependent Protein Kinases / Q000378:metabolism*; D003600:Cytosol / Q000201:enzymology; D004264:DNA Topoisomerases, Type I / Q000096:biosynthesis* / Q000235:genetics; D004305:Dose-Response Relationship, Drug; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects*; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D007940:Leukemia L5178 / Q000201:enzymology; D051379:Mice; D012333:RNA, Messenger / Q000096:biosynthesis
D012333:RNA, Messenger; D003994:Bucladesine; D017868:Cyclic AMP-Dependent Protein Kinases; D004264:DNA Topoisomerases, Type I