Cre recombinase-dependent expression of a constitutively active mutant allele of the catalytic subunit of protein kinase A.
Using the cre-loxP recombination system, we generated a line of mice expressing a constitutively active catalytic subunit of Protein Kinase A (PKA) in a temporally and spatially regulated fashion. In the absence of cre recombinase the modified catalytic subunit allele is functionally silent, but after recombination the mutant allele is expressed, resulting in enhanced PKA effects at basal cAMP levels. Mice expressing the modified protein in hepatocytes using albumin-cre transgenics show defects in glucose homeostasis, glycogen storage, fructose 2,6-bisphosphate levels, and induction of glucokinase mRNA during feeding. Similar to animals lacking glucokinase in the liver (Postic et al.: J Biol Chem 274:305-315, 1999), these mice also have defects in glucose-stimulated insulin secretion, a hallmark of Type II diabetes. The widespread expression of PKA and the involvement of this kinase in a myriad of signaling pathways suggest that these animals will provide critical tools for the study of PKA function in vivo.
Niswender
Colleen M
CM
Department of Pharmacology, University of Washington, Seattle, WA 98195, USA.
Willis
Brandon S
BS
Wallen
Angela
A
Sweet
Ian R
IR
Jetton
Thomas L
TL
Thompson
Brian R
BR
Wu
Chaodong
C
Lange
Alex J
AJ
McKnight
G Stanley
GS
D000818:Animals; D001483:Base Sequence; D001786:Blood Glucose / Q000378:metabolism; D054746:Cyclic AMP-Dependent Protein Kinase Type II; D017868:Cyclic AMP-Dependent Protein Kinases / Q000235:genetics* / Q000378:metabolism; D005786:Gene Expression Regulation; D018390:Gene Targeting; D044882:Glucose Metabolism Disorders / Q000235:genetics / Q000378:metabolism*; D005951:Glucose Tolerance Test; D007328:Insulin / Q000097:blood / Q000378:metabolism; D000078790:Insulin Secretion; D019426:Integrases / Q000235:genetics* / Q000378:metabolism; D051379:Mice; D016254:Mutagenesis, Insertional; D009154:Mutation; D012333:RNA, Messenger / Q000378:metabolism; D015398:Signal Transduction
D001786:Blood Glucose; D007328:Insulin; D012333:RNA, Messenger; D054746:Cyclic AMP-Dependent Protein Kinase Type II; D017868:Cyclic AMP-Dependent Protein Kinases; C045073:Cre recombinase; D019426:Integrases