Telokin expression in A10 smooth muscle cells requires serum response factor

B. Paul Herring, Aiping Fan Smith

Research output: Contribution to journalArticlepeer-review

44 Scopus citations


Telokin transcription is initiated from a smooth muscle-specific promoter located in an intron of the smooth muscle myosin light chain kinase gene. We have previously identified a 310-base pair fragment of the promoter that mediates A10 smooth muscle cell-specific expression of telokin. In the current study, telokin-luciferase reporter gene assays in A10 cells and REF52 nonmuscle cells revealed that the promoter region between -81 and +80 contains the regulatory elements required to mediate the in vitro cell specificity of the promoter. Several positive-acting elements, including an E box, myocyte enhancer factor 2 (MEF2)-TATA box, and CArG-serum response element, were identified within this region. Telokin transcription in A10 smooth muscle cells requires all three transcription initiation sites and an AT-rich sequence between -71 and -62 that includes a TATA box. MEF2 interacts with the AT-rich region with low affinity; however, MEF2 binding is not required for transcriptional activity in A10 cells. Binding of serum response factor (SRF) to a CArG element proximal to the TATA sequence is also critical for high levels of transcription in A10 cells. Together these data suggest that an AT-rich motif, acting in concert with SRF and an unusual transcription initiation mechanism, is required for the cell-specific expression of the telokin promoter in A10 smooth muscle cells.

Original languageEnglish (US)
Pages (from-to)C1394-C1404
JournalAmerican Journal of Physiology - Cell Physiology
Issue number4 41-4
StatePublished - Jan 1 1997


  • gene regulation
  • myosin light chain kinase
  • promoter

ASJC Scopus subject areas

  • Clinical Biochemistry
  • Cell Biology
  • Physiology
  • Physiology (medical)

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