Proteins encoded by human Down syndrome critical region gene 1-like 2 (DSCR1L2) mRNA and by a novel DSCR1L2 mRNA isoform interact with cardiac troponin I (TNNI3)

Silvia Canaider, Federica Facchin, Cristiana Griffoni, Raffaella Casadei, Lorenza Vitale, Luca Lenzi, Flavia Frabetti, Pietro D'Addabbo, Paolo Carinci, Maria Zannotti, Pierluigi Strippoli

Research output: Contribution to journalArticlepeer-review

Abstract

Down syndrome critical region gene 1-like 2 (DSCR1L2) belongs to the human DSCR1-like gene family, which also includes DSCR1 and DSCR1L1. Both DSCR1 and DSCR1L1 proteins interact with calcineurin, a calcium/calmodulin-dependent phosphatase. To date, no interactor has been described for DSCR1L2. The aim of this work was to perform a first functional study of DSCR1L2 using yeast two-hybrid analysis conducted on a human heart cDNA library. Here, we report the interaction between DSCR1L2 and the human cardiac troponin I (TNNI3), the heart-specific inhibitory subunit of the troponin complex, a central component of the contractile apparatus. This interaction was confirmed by both yeast cotransformation and GST (glutathione-sepharose transferase) fusion protein assay. Moreover, a new DSCR1L2 mRNA isoform, generated by alternative splicing, was identified and cloned in different tissues: it lacks two central exons, encoding the most conserved domains among the DSCR1-like protein family. A quantitative relative reverse transcription-polymerase chain reaction (RT-PCR) assay showed that in heart tissue the normalized expression level ratio for DSCR1L2 and DSCR1L2-E2E5 mRNA isoforms is 3.5 : 1, respectively. The yeast cotransformation and GST fusion protein assay demonstrated the interaction between this new DSCR1L2 variant and the human cardiac troponin I and the prominent role of DSCR1L2 exon 2 in determining binding between both DSCR1L2 isoforms and TNNI3. These data indicate an entirely new role for a DSCR1-like family gene, suggesting a possible involvement of DSCR1L2 in cardiac contraction.

Original languageEnglish
Pages (from-to)128-136
Number of pages9
JournalGene
Volume372
Issue number1-2
DOIs
Publication statusPublished - May 10 2006

Keywords

  • Alternative splicing
  • Human heart
  • Two-hybrid system techniques

ASJC Scopus subject areas

  • Genetics

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