TY - JOUR
T1 - Differential influence of cAMP on the expression of the three subtypes (ATA1, ATA2, and ATA3) of the amino acid transport system A
AU - Hatanaka, Takahiro
AU - Huang, Wei
AU - Martindale, Robert G.
AU - Ganapathy, Vadivel
N1 - Funding Information:
This work was supported by National Institutes of Health Grant HD 33347 and by Chugai Pharmaceutical Company, Japan.
PY - 2001/9/14
Y1 - 2001/9/14
N2 - Treatment of HepG2 cells with forskolin led to 60-100% stimulation of system A activity, measured as the Na+-dependent uptake of α-(methylamino)isobutyric acid. The stimulation was reproducible with cholera toxin and dibutyryl cAMP, and inhibitable by H7, a non-specific protein kinase inhibitor. The stimulatory effect was eliminated by cycloheximide and actinomycin D. The forskolin effect was associated with an increase in the maximal velocity of the transport system, with no change in substrate affinity. These cells express three different subtypes of system A (ATA1, ATA2, and ATA3). Treatment with forskolin increased the steady-state levels of ATA1 and ATA2 mRNAs, but decreased that of ATA3 mRNA.
AB - Treatment of HepG2 cells with forskolin led to 60-100% stimulation of system A activity, measured as the Na+-dependent uptake of α-(methylamino)isobutyric acid. The stimulation was reproducible with cholera toxin and dibutyryl cAMP, and inhibitable by H7, a non-specific protein kinase inhibitor. The stimulatory effect was eliminated by cycloheximide and actinomycin D. The forskolin effect was associated with an increase in the maximal velocity of the transport system, with no change in substrate affinity. These cells express three different subtypes of system A (ATA1, ATA2, and ATA3). Treatment with forskolin increased the steady-state levels of ATA1 and ATA2 mRNAs, but decreased that of ATA3 mRNA.
KW - Amino acid transport
KW - Cyclic AMP
KW - Human liver cell line
KW - Subtypes of system a
KW - Transport regulation
UR - http://www.scopus.com/inward/record.url?scp=0035860406&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0035860406&partnerID=8YFLogxK
U2 - 10.1016/S0014-5793(01)02848-4
DO - 10.1016/S0014-5793(01)02848-4
M3 - Article
C2 - 11566196
AN - SCOPUS:0035860406
SN - 0014-5793
VL - 505
SP - 317
EP - 320
JO - FEBS Letters
JF - FEBS Letters
IS - 2
ER -