Identification, cloning and characterization of a novel 47 kDa murine PKA C subunit homologous to human and bovine Cbeta2.
BACKGROUND
Two main genes encoding the catalytic subunits Calpha and Cbeta of cyclic AMP dependent protein kinase (PKA) have been identified in all vertebrates examined. The murine, bovine and human Cbeta genes encode several splice variants, including the splice variant Cbeta2. In mouse Cbeta2 has a relative molecular mass of 38 kDa and is only expressed in the brain. In human and bovine Cbeta2 has a relative molecular mass of 47 kDa and is mainly expressed in lymphoid tissues.


RESULTS
We identified a novel 47 kDa splice variant encoded by the mouse Cbeta gene that is highly expressed in lymphoid cells. Cloning, expression, and production of a sequence-specific antiserum and characterization of PKA catalytic subunit activities demonstrated the 47 kDa protein to be a catalytically active murine homologue of human and bovine Cbeta2. Based on the present results and the existence of a human brain-specifically expressed Cbeta splice variant designated Cbeta4 that is identical to the former mouse Cbeta2 splice variant, the mouse splice variant has now been renamed mouse Cbeta4.


CONCLUSIONS
Murine lymphoid tissues express a protein that is a homologue of human and bovine Cbeta2. The murine Cbeta gene encodes the splice variants Cbeta1, Cbeta2, Cbeta3 and Cbeta4, as is the case with the human Cbeta gene.
Funderud
Ane
A
Department of Nutrition Research, Institute of Basic Medical Sciences, University of Oslo, PO Box 1046 Blindern, 0317 Oslo, Norway. ane.funderud@medisin.uio.no
Henanger
Heidi H
HH
Hafte
Tilahun T
TT
Amieux
Paul S
PS
Orstavik
Sigurd
S
Skålhegg
Bjørn S
BS
D017398:Alternative Splicing; D000818:Animals; D002417:Cattle; D002460:Cell Line; D003001:Cloning, Molecular; D054751:Cyclic AMP-Dependent Protein Kinase Catalytic Subunits; D017868:Cyclic AMP-Dependent Protein Kinases / Q000235:genetics* / Q000378:metabolism; D014644:Genetic Variation; D006801:Humans; D007527:Isoenzymes / Q000235:genetics* / Q000378:metabolism; D008221:Lymphoid Tissue / Q000201:enzymology*; D051379:Mice; D008970:Molecular Weight; D011994:Recombinant Proteins / Q000378:metabolism; D013154:Spleen / Q000201:enzymology*; D014162:Transfection
D007527:Isoenzymes; D011994:Recombinant Proteins; D054751:Cyclic AMP-Dependent Protein Kinase Catalytic Subunits; D017868:Cyclic AMP-Dependent Protein Kinases; C463959:protein kinase A Calpha