Transcriptional and posttranscriptional regulation of the CTNS gene

Serena Corallini, Anna Taranta, Francesco Bellomo, Alessia Palma, Anna Pastore, Francesco Emma

Research output: Contribution to journalArticlepeer-review

Abstract

Cell cysteine (Cys) levels and/or the [Cys/CySS] redox potential have been shown to regulate mRNA levels of the CTNS gene, which encodes for a lysosomal cystine (CySS) carrier that is defective in cystinosis. To investigate the mechanisms involved CTNS mRNA regulation, different portions of the CTNS promotor were cloned into a luciferase vector and transfected in HK2 cells. A 1.5-2.4-fold increase in luciferase activity was observed when cells were incubated in culture medium containing low CySS concentrations. Conversely, CTNS mRNA levels decreased by 47-56% in the presence of N-acetyl-L-cysteine (NAC). Chase experiments with actinomycin D (ActD) demonstrated a 3-fold stabilization of the CTNS mRNA when cells were cultured in low CySS medium for 48 h. Treatment of control cells with cyclohexamide (CHX) increased CTNS mRNA levels, suggesting that CHX blocked the synthesis of proteins involved in mRNA degradation or in repression of the CTNS gene. Finally, in vitro binding assays showed increased binding (30-110%) of the Sp-1 transcription factor to two regions of the CTNS promotor when cells were incubated in low CySS medium. These results indicate that the CTNS gene is actively regulated at the transcriptional and posttranscriptional levels and suggest that CTNS plays a pivotal role in regulating cell thiol concentrations.

Original languageEnglish
Pages (from-to)130-135
Number of pages6
JournalPediatric Research
Volume70
Issue number2
DOIs
Publication statusPublished - Aug 2011

ASJC Scopus subject areas

  • Pediatrics, Perinatology, and Child Health

Fingerprint Dive into the research topics of 'Transcriptional and posttranscriptional regulation of the CTNS gene'. Together they form a unique fingerprint.

Cite this