The activation-dependent induction of APN-(CD13) in T-cells is controlled at different levels of gene expression.
Recently, it was shown that aminopeptidase N (E.C. 3.4.11.2, CD13) is up-regulated during mitogenic stimulation of peripheral T-cells. In this study, we demonstrate that the half-life of APN mRNA was considerably prolonged in these cells leading to a 2.7-fold increase of APN transcript level. The apparent half-life time of the APN transcript was investigated by the RNA synthesis inhibitor-chase method using actinomycin D. The steady-state APN mRNA levels was determined by a competitive RT-PCR. The half-lives estimated in resting T-cells, natural killer cells and permanently growing tumour cells varied between 3.5 and 6 h. Finally, nuclear run-on assays revealed that the APN gene expression of stimulated T-cells is controlled by increased promoter activity as well. These studies suggest a control of APN gene expression at the post-transcriptional level in addition to promoter-mediated regulation.
Wex
T
T
Institute of Experimental Internal Medicine, Department of Internal Medicine, University of Magdeburg, Germany. thomas.wex@medizin.uni-magdeburg.de
Bühling
F
F
Arndt
M
M
Frank
K
K
Ansorge
S
S
Lendeckel
U
U
D001667:Binding, Competitive; D018826:CD13 Antigens / Q000096:biosynthesis* / Q000235:genetics; D002460:Cell Line; D003609:Dactinomycin / Q000494:pharmacology; D004789:Enzyme Activation; D004790:Enzyme Induction; D004795:Enzyme Stability; D006207:Half-Life; D007700:Kinetics; D016133:Polymerase Chain Reaction; D011401:Promoter Regions, Genetic; D012333:RNA, Messenger / Q000378:metabolism; D013601:T-Lymphocytes / Q000201:enzymology*
D012333:RNA, Messenger; D003609:Dactinomycin; D018826:CD13 Antigens