Novel function of the poly(c)-binding protein α-CP2 as a transcriptional activator that binds to single-stranded DNA sequences

Duk Hee Kang, Kyu Young Song, Li Na Wei, Ping Yee Law, Horace H. Loh, Hack Sun Choi

Research output: Contribution to journalArticle

2 Scopus citations

Abstract

α-complex protein 2 (α-CP2) is known as an RNA-binding protein that interacts in a sequence-specific manner with single-stranded polycytosine [poly(C)]. This protein is involved in various post-transcriptional regulations, such as mRNA stabilization and translational regulation. In this study, the full-length mouse α-CP2 gene was expressed in an insoluble form with an N-terminal histidine tag in Escherichia coli and purified for homogeneity using affinity column chromatography Its identity was confirmed using matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry. Recombinant α-CP2 was expressed and refolded. The protein folding conditions for denatured α-CP2 were optimized. DNA and RNA electrophoretic mobility shift assays demonstrated that the recombinant α-CP2 is capable of binding to both single-stranded DNA and RNA poly(C) sequences. Furthermore, plasmids expressing α-CP2 activated the expression of a luciferase reporter when co-transfected with a single-stranded (pGL-SS) construct containing a poly(C) sequence. To our knowledge, this study demonstrates for the first time that α-CP2 functions as a transcriptional activator by binding to a single-stranded poly(C) sequence.

Original languageEnglish (US)
Pages (from-to)1187-1194
Number of pages8
JournalInternational journal of molecular medicine
Volume32
Issue number5
DOIs
StatePublished - Nov 1 2013

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Keywords

  • Electrophoretic mobility shift assays
  • Poly(C) sequence
  • Post-transcriptional regulation
  • Transcriptional activator
  • Transcriptional regulation
  • α-complex protein 2

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