Pathway Map Details

Mechanisms of CFTR activation by S-nitrosoglutathione (normal and CF)

view in full size
| open in MetaCore

Object list (links open in MetaCore):

Hdj-1, HSP90, O(2), None, S-Nitrosoglutathione extracellular region (on the apical side of membrane), HSP70, CFTR, O(2)(-), SP3, ONOO(-), SOD1,, Glutathione disulfide, , Glutathione,, HSP90 alpha, NO extracellular region, HSC70, iNOS, , NO, S-Nitroso- cysteinyl- glycine, eNOS, Cl(-) extracellular region, H(2)O(2), , S-Nitrosoglutathione, TXNRD2, Spontanous reaction, Aha1, S-Nitrosoglutathione extracellular region, nNOS, Cl(-) cytosol, Glutathione sulfinamide, TXNRD1, Csp,, CFTR, HSP90 beta, HSP90 alpha, TXNRD3, ADHX (GSNOR), (L)-Arginine, Glutathione extracellular region, Ceruloplasmin, Gamma GT, SP1,


Mechanisms of CFTR activation by S-nitrosoglutathione (normal and CF)

Cystic fibrosis (CF) is a multisystem disease associated with mutations in the gene encoding the CF transmembrane conductance regulatory ( CFTR ) protein [1]. CFTR has several functions but is typically regarded as an apical membrane Cl - channel in epithelial cells. Its post-translational processing involves complex and incompletely defined series of interactions with variety of chaperones and co-chaperones that assist in proper folding, of CFTR, as well as its glycosylation, and assess the folded protein it for possible defects. The most common mutation associated with CF, deltaF508, results in a single amino acid deletion [2], [3]. The majority of wild-type (wt) CFTR, and virtually all deltaF508 CFTR, is degraded before reaching the cell surface [4], [5]. Certain agents and conditions increase expression, maturation, and function of deltaF508 CFTR [6].

S -Nitrosoglutathione is an endogenous bronchodilator and signaling molecule [7] that enhances expression, maturation, and function of both wt and deltaF508 CFTR in epithelial cells [8], [9], [10]. S-Nitrosoglutathione is present endogenously on the apical side of airway epithelium. It increases ciliary beat frequency, thereby improving mucociliary clearance [11].

Nitric oxide synthases (NOSs) are involved in conversion of L-arginine into nitric oxide ( NO ). NO, in turn, is involved in production of S-nitrosothiols, including S-Nitrosoglutathione. NO may react directly with thiyl radicals or with thiols to form S-nitrosothiols or S-nitrosothiol radicals, respectively [12], [13], [14].

In human, there are three isoforms of NOS: neuronal NOS ( nNOS ), endothelial NOS ( eNOS ) and inducible NOS ( iNOS ). nNOS and eNOS are constitutively expressed and produce small amounts of NO, whereas iNOS expression is mainly induced by inflammatory stimuli. Induced iNOS synthesizes relatively large quantities of NO. All three isoforms are expressed in human airways [13].

In the case of CF, airway epithelial cells are more susceptible to bacterial and viral infection due to impairment of the host NO defense pathway. Polymorphisms of constitutive NOS ( nNOS and eNOS ) and reduced iNOS expression contributes to decreased NO production along with bacterial consumption [15], [16], [17], [13], [18].

S-nitrosylation can functionally regulate the general activities of Heat shock protein 90kDa alpha ( HSP90 alpha ) and provide a feedback mechanism for limiting eNOS activation. S-Nitrosoglutathione covalently modifies a susceptible cysteine residue in the HSP90 alpha domain that interacts with eNOS. On the one hand, S-nitrosylation abolishes the positive regulation on eNOS activity mediated by native chaperone HSP90 alpha [19]. On the other hand, direct S-nitrosylation can increase the activity of each of the major forms of nitric oxide synthases ( nNOS, eNOS and iNOS ) [20].

Ceruloplasmin also may catalyze the synthesis of S-Nitrosoglutathione [21], [22], [14].

S -Nitrosoglutathione can be catabolized by a number of enzymes, including Cu/Zn superoxide dismutase ( SOD1 ), gamma glutamyl transpeptidase ( Gamma GT ), thioredoxin reductases ( TXNRD1, TXNRD2 and TXNRD3 ) and glutathione-dependent formaldehyde dehydrogenase ( ADHX (GSNOR) ) [23], [24], [25], [26], [27], [28], [22], [11].

Gamma GT can be involved in CFTR activation. S-Nitrosocysteinylglycine, the product of S-Nitrosoglutathione cleavage by Gamma GT, can increase DeltaF508 CFTR maturation [29].

SOD1, TXNRD1, TXNRD2 and TXNRD3 catabolize S-Nitrosoglutathione to form free NO radicals [23], [28], [22], [11]. Free NO can spontaneously react with Superoxide anion radical ( O(2)(-) ) to produce Peroxynitrite ( ONOO(-) ) [30]. The presence of SOD1, that catalyzes the dismutation of O(2)(-), can outcompete the peroxynitrite reaction. Cells may contain sufficient SOD1 to prevent inactivation of NO by O(2)(-) [12].

S -Nitrosoglutathione at low micromolar concentrations increases the DeltaF508 and wild-type CFTR expression and maturation. S-Nitrosoglutathione mainly acts independently of the classic NO radical/cyclic GMP pathway [29].

The effect of S-Nitrosoglutathione at 1-10 microM concentration is partly transcriptional (it acts via increasing transcription factors SP1 and SP3 expression and their DNA-binding capacity) [9] and partly post-translational [8], [29]. For SP1, the additional mechanism for enhanced DNA-binding involves cysteine S-nitrosylation in the SP1 zinc finger-binding domain [9].

On the other hand, S-Nitrosoglutathione at nitrosative stress levels (100 microM) inhibits SP3 binding, augments competitive binding of SP1 and inhibits CFTR transcription [9].

Post-translational effect of S-Nitrosoglutathione is associated with both increased expression and covalent modification - namely S-nitrosylation - of proteins involved in CFTR folding, and stabilization resulted in an increased CFTR maturation [8], [29].

ER-associated pathways of CFTR folding are affected by chaperones and co-chaperones such as cytosolic Heat shock proteins 70 and 90kDa ( HSP70 and HSP90 ), DnaJ homolog subfamily B member ( Hdj-1 ) and others [31], [32], [33].

HSP90 ( HSP90 alpha and HSP90 beta ) and Heat shock 70kDa protein 8 ( HSC70 ) are S-nitrosylated by S-Nitrosoglutathione, followed by CFTR folding and stabilization [29].

S -Nitrosoglutathione also increases expression of DnaJ homolog, subfamily C, member 5 ( Csp ) to enhance the association between Csp and CFTR in the ER and Golgi. S-Nitrosoglutathione does not S-nitrosylate Csp. S-Nitrosoglutathione actually increases Csp expression (primarily post-transcriptionally) leading to increase in CFTR folding and maturation [29].

In the absence of S-Nitrosoglutathione, Csp initiates activation of HSC70 ATPase activity, which leads to CFTR degradation [34], [35], [36]., This degradation is inhibited in the presence of S-Nitrosoglutathione, allowing increased Csp to continue stabilization of CFTR. HSC70 has a single critical cysteine residue in its ATP binding domain. S-nitrosylation of this cysteine allows Csp to augment CFTR folding without leading to CFTR degradation [29].


  1. Rowe SM, Miller S, Sorscher EJ
    Cystic fibrosis. The New England journal of medicine 2005 May 12;352(19):1992-2001
  2. Gibson RL, Burns JL, Ramsey BW
    Pathophysiology and management of pulmonary infections in cystic fibrosis. American journal of respiratory and critical care medicine 2003 Oct 15;168(8):918-51
  3. Dubin PJ, McAllister F, Kolls JK
    Is cystic fibrosis a TH17 disease? Inflammation research : official journal of the European Histamine Research Society ... [et al.] 2007 Jun;56(6):221-7
  4. Kopito RR
    Biosynthesis and degradation of CFTR. Physiological reviews 1999 Jan;79(1 Suppl):S167-73
  5. Amaral MD
    CFTR and chaperones: processing and degradation. Journal of molecular neuroscience : MN 2004;23(1-2):41-8
  6. Verkman AS
    Drug discovery in academia. American journal of physiology. Cell physiology 2004 Mar;286(3):C465-74
  7. Gaston B, Reilly J, Drazen JM, Fackler J, Ramdev P, Arnelle D, Mullins ME, Sugarbaker DJ, Chee C, Singel DJ
    Endogenous nitrogen oxides and bronchodilator S-nitrosothiols in human airways. Proceedings of the National Academy of Sciences of the United States of America 1993 Dec 1;90(23):10957-61
  8. Zaman K, McPherson M, Vaughan J, Hunt J, Mendes F, Gaston B, Palmer LA
    S-nitrosoglutathione increases cystic fibrosis transmembrane regulator maturation. Biochemical and biophysical research communications 2001 Jun 1;284(1):65-70
  9. Zaman K, Palmer LA, Doctor A, Hunt JF, Gaston B
    Concentration-dependent effects of endogenous S-nitrosoglutathione on gene regulation by specificity proteins Sp3 and Sp1. The Biochemical journal 2004 May 15;380(Pt 1):67-74
  10. Chen L, Patel RP, Teng X, Bosworth CA, Lancaster JR Jr, Matalon S
    Mechanisms of cystic fibrosis transmembrane conductance regulator activation by S-nitrosoglutathione. The Journal of biological chemistry 2006 Apr 7;281(14):9190-9
  11. Zeitlin PL
    Is it go or NO go for S-nitrosylation modification-based therapies of cystic fibrosis transmembrane regulator trafficking? Molecular pharmacology 2006 Oct;70(4):1155-8
  12. Mayer B, Pfeiffer S, Schrammel A, Koesling D, Schmidt K, Brunner F
    A new pathway of nitric oxide/cyclic GMP signaling involving S-nitrosoglutathione. The Journal of biological chemistry 1998 Feb 6;273(6):3264-70
  13. de Winter-de Groot KM, van der Ent CK
    Nitric oxide in cystic fibrosis. Journal of cystic fibrosis : official journal of the European Cystic Fibrosis Society 2005 Aug;4 Suppl 2:25-9
  14. Gaston B, Singel D, Doctor A, Stamler JS
    S-nitrosothiol signaling in respiratory biology. American journal of respiratory and critical care medicine 2006 Jun 1;173(11):1186-93
  15. Kelley TJ, Drumm ML
    Inducible nitric oxide synthase expression is reduced in cystic fibrosis murine and human airway epithelial cells. The Journal of clinical investigation 1998 Sep 15;102(6):1200-7
  16. Grasemann H, Storm van's Gravesande K, Buscher R, Knauer N, Silverman ES, Palmer LJ, Drazen JM, Ratjen F
    Endothelial nitric oxide synthase variants in cystic fibrosis lung disease. American journal of respiratory and critical care medicine 2003 Feb 1;167(3):390-4
  17. Zheng S, Xu W, Bose S, Banerjee AK, Haque SJ, Erzurum SC
    Impaired nitric oxide synthase-2 signaling pathway in cystic fibrosis airway epithelium. American journal of physiology. Lung cellular and molecular physiology. 2004 Aug;287(2):L374-81
  18. Moeller A, Horak F Jr, Lane C, Knight D, Kicic A, Brennan S, Franklin P, Terpolilli J, Wildhaber JH, Stick SM
    Inducible NO synthase expression is low in airway epithelium from young children with cystic fibrosis. Thorax 2006 Jun;61(6):514-20
  19. Mart?-nez-Ruiz A, Villanueva L, Gonz??lez de Ordu??a C, L??pez-Ferrer D, Higueras MA, Tar?-n C, Rodr?-guez-Crespo I, V??zquez J, Lamas S
    S-nitrosylation of Hsp90 promotes the inhibition of its ATPase and endothelial nitric oxide synthase regulatory activities. Proceedings of the National Academy of Sciences of the United States of America 2005 Jun 14;102(24):8525-30
  20. Gow AJ, Chen Q, Hess DT, Day BJ, Ischiropoulos H, Stamler JS
    Basal and stimulated protein S-nitrosylation in multiple cell types and tissues. The Journal of biological chemistry 2002 Mar 22;277(12):9637-40
  21. Inoue K, Akaike T, Miyamoto Y, Okamoto T, Sawa T, Otagiri M, Suzuki S, Yoshimura T, Maeda H
    Nitrosothiol formation catalyzed by ceruloplasmin. Implication for cytoprotective mechanism in vivo. The Journal of biological chemistry 1999 Sep 17;274(38):27069-75
  22. Gaston BM, Carver J, Doctor A, Palmer LA
    S-nitrosylation signaling in cell biology. Molecular interventions 2003 Aug;3(5):253-63
  23. Nikitovic D, Holmgren A
    S-nitrosoglutathione is cleaved by the thioredoxin system with liberation of glutathione and redox regulating nitric oxide. The Journal of biological chemistry 1996 Aug 9;271(32):19180-5
  24. Henson SE, Nichols TC, Holers VM, Karp DR
    The ectoenzyme gamma-glutamyl transpeptidase regulates antiproliferative effects of S-nitrosoglutathione on human T and B lymphocytes. Journal of immunology (Baltimore, Md. : 1950) 1999 Aug 15;163(4):1845-52
  25. Liu L, Hausladen A, Zeng M, Que L, Heitman J, Stamler JS
    A metabolic enzyme for S-nitrosothiol conserved from bacteria to humans. Nature 2001 Mar 22;410(6827):490-4
  26. H????g JO, Str??mberg P, Hedberg JJ, Griffiths WJ
    The mammalian alcohol dehydrogenases interact in several metabolic pathways. Chemico-biological interactions 2003 Feb 1;143-144:175-81
  27. Hedberg JJ, Griffiths WJ, Nilsson SJ, H????g JO
    Reduction of S-nitrosoglutathione by human alcohol dehydrogenase 3 is an irreversible reaction as analysed by electrospray mass spectrometry. European journal of biochemistry / FEBS 2003 Mar;270(6):1249-56
  28. Romeo AA, Capobianco JA, English AM
    Superoxide dismutase targets NO from GSNO to Cysbeta93 of oxyhemoglobin in concentrated but not dilute solutions of the protein. Journal of the American Chemical Society 2003 Nov 26;125(47):14370-8
  29. Zaman K, Carraro S, Doherty J, Henderson EM, Lendermon E, Liu L, Verghese G, Zigler M, Ross M, Park E, Palmer LA, Doctor A, Stamler JS, Gaston B
    S-nitrosylating agents: a novel class of compounds that increase cystic fibrosis transmembrane conductance regulator expression and maturation in epithelial cells. Molecular pharmacology 2006 Oct;70(4):1435-42
  30. Stamler JS, Lamas S, Fang FC
    Nitrosylation. the prototypic redox-based signaling mechanism. Cell 2001 Sep 21;106(6):675-83
  31. Loo MA, Jensen TJ, Cui L, Hou Y, Chang XB, Riordan JR
    Perturbation of Hsp90 interaction with nascent CFTR prevents its maturation and accelerates its degradation by the proteasome. The EMBO journal 1998 Dec 1;17(23):6879-87
  32. Farinha CM, Nogueira P, Mendes F, Penque D, Amaral MD
    The human DnaJ homologue (Hdj)-1/heat-shock protein (Hsp) 40 co-chaperone is required for the in vivo stabilization of the cystic fibrosis transmembrane conductance regulator by Hsp70. The Biochemical journal 2002 Sep 15;366(Pt 3):797-806
  33. Wang X, Venable J, Lapointe P, Hutt DM, Koulov AV, Coppinger J, Gurkan C, Kellner W, Matteson J, Plutner H, Riordan JR, Kelly JW, Yates JR 3rd, Balch WE
    Hsp90 Cochaperone Aha1 Downregulation Rescues Misfolding of CFTR in Cystic Fibrosis. Cell 2006 Nov 17;127(4):803-15
  34. Braun JE, Wilbanks SM, Scheller RH
    The cysteine string secretory vesicle protein activates Hsc70 ATPase. The Journal of biological chemistry 1996 Oct 18;271(42):25989-93
  35. Chamberlain LH, Burgoyne RD
    Activation of the ATPase activity of heat-shock proteins Hsc70/Hsp70 by cysteine-string protein. The Biochemical journal 1997 Mar 15;322 ( Pt 3):853-8
  36. Meacham GC, Patterson C, Zhang W, Younger JM, Cyr DM
    The Hsc70 co-chaperone CHIP targets immature CFTR for proteasomal degradation. Nature cell biology 2001 Jan;3(1):100-5