Role of PRL-3, a human muscle-specific tyrosine phosphatase, in angiotensin-II signaling.
Action of protein kinases and phosphatases contributes to myocardial hypertrophy. PRL-3, a protein tyrosine phosphatase, was identified in a cDNA library from an explanted human heart obtained from a patient with idiopathic cardiomyopathy. PRL-3 is expressed in heart and skeletal muscle, exhibiting approximately 76% identity to the ubiquitous tyrosine phosphatase PRL-1, which was reported to increase cell proliferation. PRL-3 was cloned into E. coli and purified using affinity chromatography. PRL-3 activity was determined using the substrate 6,8-difluoro-4-methylumbelliferyl phosphate, and was inhibited by vanadate and analogs. HEK293 cells expressing PRL-3 demonstrated increased growth rates versus nontransfected cells or cells transfected with the catalytically inactive C104S PRL-3 mutant. The tyrosine phosphatase inhibitor, potassium bisperoxo (bipyridine) oxovanadate V, normalizes the growth rate of PRL-3 expressing cells to that of parental HEK293 cells in a concentration-dependent manner. Using FLIPR analysis, parental HEK293 cells mobilize calcium when stimulated with angiotensin-II (AngII). However, calcium mobilization is inhibited in cells expressing wild-type PRL-3 when stimulated with AngII, while cells expressing the inactive mutant of PRL-3 mobilize calcium to the same extent as parental HEK293 cells. Western blots comparing PRL-3 transfected cells to parental HEK293 cells showed dephosphorylation of p130(cas) in response to AngII. These data suggest a role for PRL-3 in the modulation of intracellular calcium transients induced by AngII.
Matter
W F
WF
Cardiovascular Research, Eli Lilly and Company, Indianapolis, Indiana 46285, USA.
Estridge
T
T
Zhang
C
C
Belagaje
R
R
Stancato
L
L
Dixon
J
J
Johnson
B
B
Bloem
L
L
Pickard
T
T
Donaghue
M
M
Acton
S
S
Jeyaseelan
R
R
Kadambi
V
V
Vlahos
C J
CJ
D019943:Amino Acid Substitution; D000804:Angiotensin II / Q000494:pharmacology*; D002118:Calcium / Q000378:metabolism*; D020013:Calcium Signaling / Q000187:drug effects / Q000502:physiology*; D009202:Cardiomyopathies / Q000201:enzymology / Q000235:genetics; D002455:Cell Division / Q000187:drug effects; D002460:Cell Line; D002846:Chromatography, Affinity; D003001:Cloning, Molecular; D003600:Cytosol / Q000378:metabolism; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004926:Escherichia coli; D015723:Gene Library; D006801:Humans; D017874:Immediate-Early Proteins / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism*; D018482:Muscle, Skeletal / Q000201:enzymology*; D016297:Mutagenesis, Site-Directed; D009206:Myocardium / Q000201:enzymology; D009363:Neoplasm Proteins; D009924:Organ Culture Techniques; D009942:Organometallic Compounds / Q000494:pharmacology; D010618:Phenanthrolines / Q000494:pharmacology; D017027:Protein Tyrosine Phosphatases / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism*; D011994:Recombinant Proteins / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism; D015398:Signal Transduction / Q000502:physiology*; D014162:Transfection; D014638:Vanadates / Q000494:pharmacology
D004791:Enzyme Inhibitors; D017874:Immediate-Early Proteins; D009363:Neoplasm Proteins; D009942:Organometallic Compounds; D010618:Phenanthrolines; D011994:Recombinant Proteins; D000804:Angiotensin II; D014638:Vanadates; C102120:bisperoxo(1,10-phenanthroline)oxovanadate(1-); C484730:PTP4A3 protein, human; D017027:Protein Tyrosine Phosphatases; D002118:Calcium