PROTEIN-KINASE CK2 IS ALTERED IN INSULIN-RESISTANT GENETICALLY-OBESE (FALFA) RATS

Hepatic insulin receptor levels in 6-week-old obese (fa/fa) rats were about 2-fold lower than those from lean (Fa/-) rats, which agrees with their insulin-resistant state. Nuclear protein kinase CK2 activity an d protein content in livers from obese (fa/fa) rats were similar to th ose of lean (Fa/-) animals but the cytosolic levels were reduced to ha lf, due to a decrease in the 39-kDa catalytic subunit, Marked increase s in activity, due to rises in the 44-kDa and 39-kDa catalytic subunit s, were seen in the 16 000 x g sediments (M1) from insulin-resistant r ats, with moderate changes in the 100 000 x g sediments (M2), The incr ease in CK2 binding to M1 did not require increases in the molecular c haperone grp94, which was unaltered in insulin-resistant rats. (C) 199 8 Federation of European Biochemical Societies.