Subcellular distribution of the R-subunits of cAMP-dependent protein kinase in LS-174T human colon carcinoma cells.
The analysis of the particulate preparations of LS-174T human colon carcinoma cells in confluent stage of growth revealed different distribution for regulatory subunits (R) of cAMP-dependent protein kinase (PKA) in the subcellular compartments. The LS-174T cell lysates were subjected to differential and discontinuous sucrose density gradient centrifugation. The obtained fractions were assayed for marker enzymes and photoaffinity labeled with 8-N3[32P]cAMP. The whole lysates and cytoplasmic fraction exhibited the presence of both RI alpha and RII alpha--subunits of PKA. The fractions exhibiting high activity of the marker enzymes for plasma membranes, Golgi apparatus and mitochondria contained mainly RII alpha. In the fractions of lysosomes and microsomes RI alpha and RII alpha were found in nearly equal amounts.
Cellular Biochemistry Section, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892, USA.
A A
AA
Kondrashin
M V
MV
Nesterova
Y S
YS
Cho-Chung
D002458:Cell Fractionation; D002462:Cell Membrane / Q000201:enzymology*; D002499:Centrifugation, Density Gradient; D054754:Cyclic AMP-Dependent Protein Kinase RIIalpha Subunit; D054756:Cyclic AMP-Dependent Protein Kinase RIalpha Subunit; D017868:Cyclic AMP-Dependent Protein Kinases / Q000032:analysis* / Q000302:isolation & purification*; D006056:Golgi Apparatus / Q000201:enzymology; D006801:Humans; D008247:Lysosomes / Q000201:enzymology; D008861:Microsomes / Q000201:enzymology; D008928:Mitochondria / Q000201:enzymology; D015388:Organelles / Q000201:enzymology*; D013347:Subcellular Fractions / Q000201:enzymology; D014407:Tumor Cells, Cultured
D054754:Cyclic AMP-Dependent Protein Kinase RIIalpha Subunit; D054756:Cyclic AMP-Dependent Protein Kinase RIalpha Subunit; C517834:PRKAR1A protein, human; C517819:PRKAR2A protein, human; D017868:Cyclic AMP-Dependent Protein Kinases