A possible role for intracellular GSH in spontaneous reaction of a cysteine (T338C) engineered into the Cystic Fibrosis Transmembrane Conductance Regulator

Xuehong Liu

Research output: Contribution to journalArticle

2 Citations (Scopus)

Abstract

The conductance of oocytes expressing T338C CFTR (Cystic Fibrosis Transmembrane Conductance Regulator) exhibits variable responses to dithiothreitol (DTT) and 2-mercaptoethanol (2-ME) that we proposed might be due to the extraction of copper from an adventitious binding site (Liu et al. J Biol Chem 281(12):8275-8285, 2006). In order to study the origins of variability in chemical reactivity of T338C CFTR channels, oocytes expressing T338C CFTR were exposed to BCNU (bischloroethylnitrosourea), an inhibitor of glutathione reductase. BCNU treatment caused a significant reduction of initial conductance and an increase in the response to 2-ME or DTT, suggesting a direct or indirect influence of intracellular glutathione (GSH), a major determinant of the disposition of intracellular copper. Single-channel recordings indicated that T338C CFTR channels not exposed to 2-ME or DTT exhibited multiple conductance levels not seen in T338A CFTR channels. Exposure to BCNU shifted the distribution of single-channel current amplitudes towards lower values, whereas exposure to DTT favored higher amplitudes. These results suggest that the altered chemical state of T338C channels is associated with a decreased single-channel conductance and that intracellular factors (most likely GSH) may modulate the propensity of the channel to form these altered states.

Original languageEnglish (US)
Pages (from-to)277-287
Number of pages11
JournalBioMetals
Volume21
Issue number3
DOIs
StatePublished - Jun 2008

Fingerprint

Cystic Fibrosis Transmembrane Conductance Regulator
cystic fibrosis
dithiothreitol
Dithiothreitol
Cysteine
cysteine
Mercaptoethanol
Copper
Chemical reactivity
Binding sites
Oocytes
oocytes
copper
Glutathione Reductase
glutathione-disulfide reductase
Glutathione
glutathione
binding sites
Binding Sites
beta-mercaptoethanol

Keywords

  • CFTR
  • Channel
  • Copper
  • Engineered cysteine
  • Glutathione

ASJC Scopus subject areas

  • Agricultural and Biological Sciences(all)
  • Biochemistry, Genetics and Molecular Biology(all)

Cite this

A possible role for intracellular GSH in spontaneous reaction of a cysteine (T338C) engineered into the Cystic Fibrosis Transmembrane Conductance Regulator. / Liu, Xuehong.

In: BioMetals, Vol. 21, No. 3, 06.2008, p. 277-287.

Research output: Contribution to journalArticle

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