scholarly journals Protein Kinase A-dependent Translocation of Hsp90α Impairs Endothelial Nitric-oxide Synthase Activity in High Glucose and Diabetes

2007 ◽  
Vol 282 (13) ◽  
pp. 9364-9371 ◽  
Author(s):  
Hetian Lei ◽  
Annapurna Venkatakrishnan ◽  
Soyoung Yu ◽  
Andrius Kazlauskas
Keyword(s):  
Nitric Oxide ◽  
Protein Kinase ◽  
Nitric Oxide Synthase ◽  
Protein Kinase A ◽  
High Glucose ◽  
Endothelial Nitric Oxide Synthase ◽  
Oxide Synthase ◽  
Endothelial Nitric Oxide ◽  
Nitric Oxide Synthase Activity ◽  
Kinase A

scholarly journals Inhibition of MEK/ERK1/2 signalling alters endothelial nitric oxide synthase activity in an agonist-dependent manner

2006 ◽  
Vol 398 (2) ◽  
pp. 279-288 ◽  
Author(s):  
Jacqueline M. Cale ◽  
Ian M. Bird
Keyword(s):  
Nitric Oxide ◽  
Protein Kinase ◽  
Nitric Oxide Synthase ◽  
Endothelial Nitric Oxide Synthase ◽  
Intracellular Trafficking ◽  
Enos Activity ◽  
Oxide Synthase ◽  
Endothelial Nitric Oxide ◽  
Nitric Oxide Synthase Activity

eNOS (endothelial nitric oxide synthase) activity is post-translationally regulated in a complex fashion by acylation, protein–protein interactions, intracellular trafficking and phosphorylation, among others. Signalling pathways that regulate eNOS activity include phosphoinositide 3-kinase/Akt, cyclic nucleotide-dependent kinases [PKA (protein kinase A) and PKG], PKC, as well as ERKs (extracellular-signal-regulated kinases). The role of ERKs in eNOS activation remains controversial. In the present study, we have examined the role of ERK1/2 in eNOS activation in HUVEC-CS [transformed HUVEC (human umbilical-vein endothelial cells)] as well as a widely used model for eNOS study, transiently transfected COS-7 cells. U0126 pretreatment of HUVEC-CS potentiated ATP-stimulated eNOS activity, independent of changes in intracellular Ca2+ concentration ([Ca2+]i). In COS-7 cells transiently expressing ovine eNOS, U0126 potentiated A23187-stimulated eNOS activity, but inhibited ATP-stimulated activity. Compensatory changes in phosphorylation of five key eNOS residues did not account for changes in A23187-stimulated activity. However, in the case of ATP, altered phosphorylation and changes in [Ca2+]i may partially contribute to U0126 inhibition of activity. Finally, seven eNOS alanine mutants of putative ERK1/2 targets were generated and the effects of U0126 pretreatment on eNOS activity were gauged with A23187 and ATP treatment. T97A-eNOS was the only construct significantly different from wild-type after U0126 pretreatment and ATP stimulation of eNOS activation. In the present study, eNOS activity was either potentiated or inhibited in COS-7 cells, suggesting agonist dependence for MEK/ERK1/2 signalling [where MEK is MAPK (mitogen-activated protein kinase)/ERK kinase] to eNOS and a complex mechanism including [Ca2+]i, phosphorylation and, possibly, intracellular trafficking.

Inhibition of Endothelial Nitric Oxide Synthase Activity by Protein Kinase C

Hypertension ◽  
1995 ◽  
Vol 25 (2) ◽  
pp. 180-185 ◽  
Author(s):  
Ken-ichi Hirata ◽  
Ryohei Kuroda ◽  
Tsuyoshi Sakoda ◽  
Masaya Katayama ◽  
Nobutaka Inoue ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Protein Kinase C ◽  
Protein Kinase ◽  
Nitric Oxide Synthase ◽  
Endothelial Nitric Oxide Synthase ◽  
Kinase C ◽  
Oxide Synthase ◽  
Endothelial Nitric Oxide ◽  
Nitric Oxide Synthase Activity
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