Virtually Identical Enhancers Containing a Segment of Homology to Murine 3′IgH-E(hs1,2) Lie Downstream of Human Ig Cα1 and Cα2 Genes

Chaoqun Chen, Barbara K. Birshtein

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58 Scopus citations


We have isolated sequences downstream of human Ig Cα1 and Cα2 genes and have identified two enhancers in these regions. One enhancer is located ∼9 kb downstream of Cα1, and the second enhancer is located ∼11 kb downstream of Cα2. These ∼1.6-kb enhancers are virtually identical to each other except for varying numbers of a ∼53-bp motif. The Cα2-associated enhancer contains four copies of this motif in tandem, whereas the Cα1 -associated enhancer has only a single copy. Within the human enhancers is a 177-bp segment that is homologous to a 191-bp segment of one of four enhancers from the 3′ regulatory region of murine (and rat) DNA, namely 3′IgH-E(hs1,2). Like the murine and rat enhancers, both human enhancers are flanked by inverted repeats; furthermore, the human enhancers generally appear to be inverted with respect to each other. The evolutionarily conserved region of homology has substantial core enhancer activity. Contained within this region are the single octamer and one copy of the ∼53-bp motif, both of which contribute to the activity of the full-length enhancer. A comparison of the DNA sequences and the results of transient transfection assays imply that the human Cα-associated enhancers may be regulated (in part) differently than the murine enhancer 3′IgH-E(hs1,2).

Original languageEnglish (US)
Pages (from-to)1310-1318
Number of pages9
JournalJournal of Immunology
Issue number3
StatePublished - Aug 1 1997


ASJC Scopus subject areas

  • Immunology and Allergy
  • Immunology

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