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Subcellular distribution of the R‐subunits of cAMP‐dependent protein kinase in LS‐174T human colon carcinoma cells
Author(s) -
Kondrashin A. A.,
Nesterova M. V.,
ChoChung Y. S.
Publication year - 1998
Publication title -
iubmb life
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.132
H-Index - 113
eISSN - 1521-6551
pISSN - 1521-6543
DOI - 10.1080/15216549800202602
Subject(s) - differential centrifugation , cytoplasm , protein kinase a , golgi apparatus , protein subunit , microbiology and biotechnology , enzyme , subcellular localization , cell fractionation , biochemistry , centrifugation , microsome , biology , chemistry , cell , gene
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 RIα and RIIα ‐ subunits of PKA. The fractions exhibiting high activity of the marker enzymes for plasma membranes, Golgi apparatus and mitochondria contained mainly RIIα. In the fractions of lysosomes and microsomes RIα and RIIα were found in nearly equal amounts.