Linked Life Data

17095720

Source:http://linkedlifedata.com/resource/pubmed/id/17095720

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
12
pubmed:dateCreated
2006-12-12
pubmed:abstractText
Because phospholemman (PLM) regulates the Na(+)/K(+) pump (NKA) and is a major cardiac phosphorylation target for both protein kinase A (at Ser68) and protein kinase C (PKC) (at both Ser63 and Ser68), we evaluated whether PLM mediates the PKC-dependent regulation of NKA function and protein kinase A/PKC crosstalk in ventricular myocytes. PKC was activated by PDBu (300 nmol/L), and we measured NKA-mediated [Na(+)](i) decline (fluorescence measurements) and current (I(pump)) (voltage clamp). In wild-type mouse myocytes, PDBu increased PLM phosphorylation at Ser63 and Ser68, I(pump) (both at 10 and 100 mmol/L Na(+) in the pipette solution) and maximal NKA-mediated Na(+) extrusion rate (V(max)) from 7.9+/-1.1 to 12.7+/-1.9 mmol.L(-1) per minute without altering NKA affinity for internal Na(+) (K(0.5)). In PLM knockout mice, PDBu had no effect on either V(max) or K(0.5). After pretreatment with isoproterenol (ISO) (1 mumol/L), PDBu still increased the NKA V(max) and PLM phosphorylation at Ser63 and Ser68. Conversely, after pretreatment with PDBu, ISO further increased the Na(+) affinity of NKA and phosphorylation at Ser68, as it did alone without PDBu. The final NKA activity was independent of the application sequence. The NKA activity in PLM knockout myocytes, after normalizing the protein level, was similar to that after PDBu and ISO treatment. We conclude that (1) PLM mediates the PKC-dependent activation of NKA function in cardiac myocytes, (2) PDBu and ISO effects are additive in the mouse (affecting mainly V(max) and K(0.5), respectively), and (3) PDBu and ISO combine to activate NKA in wild-type to the level found in the PLM knockout mouse.
pubmed:grant
pubmed:commentsCorrections
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
1524-4571
pubmed:author
pubmed:issnType
Electronic
pubmed:day
8
pubmed:volume
99
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1376-83
pubmed:dateRevised
2007-11-15
pubmed:meshHeading
pubmed-meshheading:17095720-Animals, pubmed-meshheading:17095720-Biological Transport, pubmed-meshheading:17095720-Carcinogens, pubmed-meshheading:17095720-Cyclic AMP-Dependent Protein Kinases, pubmed-meshheading:17095720-Heart Ventricles, pubmed-meshheading:17095720-Membrane Proteins, pubmed-meshheading:17095720-Mice, pubmed-meshheading:17095720-Mice, Inbred C57BL, pubmed-meshheading:17095720-Mice, Knockout, pubmed-meshheading:17095720-Monocytes, pubmed-meshheading:17095720-Myocytes, Cardiac, pubmed-meshheading:17095720-Phorbol 12,13-Dibutyrate, pubmed-meshheading:17095720-Phosphoproteins, pubmed-meshheading:17095720-Phosphorylation, pubmed-meshheading:17095720-Protein Kinase C, pubmed-meshheading:17095720-Serine, pubmed-meshheading:17095720-Sodium, pubmed-meshheading:17095720-Sodium-Potassium-Exchanging ATPase
pubmed:year
2006
pubmed:articleTitle
Phospholemman phosphorylation mediates the protein kinase C-dependent effects on Na+/K+ pump function in cardiac myocytes.
pubmed:affiliation
Department of Physiology, Loyola University Chicago, Stritch School of Medicine, 2160 S First Ave, Maywood, IL 60153, USA.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't, Research Support, N.I.H., Extramural