S-nitrosylating agents: a novel class of compounds that increase cystic fibrosis transmembrane conductance regulator expression and maturation in epithelial cells.
The endogenous bronchodilator, S-nitrosoglutathione (GSNO), increases expression, maturation, and function of both the wild-type and the DeltaF508 mutant of the cystic fibrosis transmembrane conductance regulatory protein (CFTR). Though transcriptional mechanisms of action have been identified, GSNO seems also to have post-transcriptional effects on CFTR maturation. Here, we report that 1) GSNO is only one of a class of S-nitrosylating agents that, at low micromolar concentrations, increase DeltaF508 and wild-type CFTR expression and maturation; 2) NO itself (at these concentrations) and 8-bromocyclic GMP are minimally active on CFTR; 3) a novel agent, S-nitrosoglutathione diethyl ester, bypasses the need for GSNO bioactivation by gamma-glutamyl transpeptidase to increase CFTR maturation; 4) surprisingly, expression-but not S-nitrosylation-of cysteine string proteins (Csp) 1 and 2 is increased by GSNO; 5) the effect of GSNO to increase full maturation of wild-type CFTR is inhibited by Csp silencing (si)RNA; 6) proteins relevant to CFTR trafficking are SNO-modified, and SNO proteins traffic through the endoplasmic reticulum (ER) and Golgi after GSNO exposure; and 7) GSNO alters the interactions of DeltaF508 CFTR with Csp and Hsc70 in the ER and Golgi. These data suggest that GSNO is one of a class of S-nitrosylating agents that act independently of the classic NO radical/cyclic GMP pathway to increase CFTR expression and maturation. They also suggest that the effect of GSNO is dependent on Csp and on intracellular SNO trafficking. We speculate that these data will be of relevance to the development of NO donor-based therapies for CF.
Zaman
Khalequz
K
Department of Pediatrics, University of Virginia Health System, Pediatric Respiratory Medicine, Box 800386, Charlottesville, VA 22908, USA.
Carraro
Silvia
S
Doherty
Joseph
J
Henderson
Edward M
EM
Lendermon
Elizabeth
E
Liu
Lei
L
Verghese
George
G
Zigler
Molly
M
Ross
Mark
M
Park
Edward
E
Palmer
Lisa A
LA
Doctor
Allan
A
Stamler
Jonathan S
JS
Gaston
Benjamin
B
D002454:Cell Differentiation; D002460:Cell Line; D019005:Cystic Fibrosis Transmembrane Conductance Regulator / Q000378:metabolism*; D004721:Endoplasmic Reticulum / Q000378:metabolism; D004847:Epithelial Cells / Q000502:physiology*; D005786:Gene Expression Regulation; D050956:HSP40 Heat-Shock Proteins / Q000502:physiology; D018840:HSP70 Heat-Shock Proteins / Q000378:metabolism; D006801:Humans; D008565:Membrane Proteins / Q000502:physiology; D015394:Molecular Structure; D011499:Protein Processing, Post-Translational; D026422:S-Nitrosoglutathione / Q000494:pharmacology*; D026403:S-Nitrosothiols / Q000494:pharmacology
D050956:HSP40 Heat-Shock Proteins; D018840:HSP70 Heat-Shock Proteins; D008565:Membrane Proteins; D026403:S-Nitrosothiols; C088460:cysteine string protein; D019005:Cystic Fibrosis Transmembrane Conductance Regulator; D026422:S-Nitrosoglutathione