SpGCF1, a sea urchin embryo DNA-binding protein, exists as five nested variants encoded by a single mRNA

Dev Biol. 1995 Jun;169(2):713-27. doi: 10.1006/dbio.1995.1181.

Abstract

Several Strongylocentrotus purpuratus gene cis-regulatory regions contain asymmetric C4 sequences which are core elements of target sites for a specific DNA-protein interaction. Blastula stage nuclear extract contains five proteins which specifically bind to these target sites, resulting in a characteristic pattern of complexes in gel mobility shift assays. We used automated affinity chromatography to purify a protein which binds to these sites and have isolated the corresponding cDNA. This protein, SpGCF1, is a novel sea urchin DNA-binding protein with no overall homology to proteins reported in the databases currently available. The DNA-binding domain of this protein was identified by a deletion analysis. As demonstrated both for protein translated in vitro and for bacterial protein expressed from a cDNA clone, a single SpGCF1 mRNA serves as a template for the synthesis of five DNA-binding polypeptides. We show that these five polypeptides are most likely produced by differential usage of a nested set of AUG start codons in the SpGCF1 cDNA and thus contain variable amounts of a proline-rich N-terminal domain. Since proline-rich regions often serve as transcriptional activation domains, the five SpGCF1 proteins apparently possess different "activation potentials."

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Base Sequence
  • Binding Sites
  • Cloning, Molecular
  • DNA / metabolism
  • DNA, Complementary
  • DNA-Binding Proteins / genetics*
  • Gene Expression Regulation, Developmental
  • Molecular Sequence Data
  • RNA, Messenger / genetics*
  • Sea Urchins / embryology
  • Sea Urchins / genetics*
  • Transcription Factors / genetics*

Substances

  • DNA, Complementary
  • DNA-Binding Proteins
  • RNA, Messenger
  • SpGCF1 protein, Strongylocentrotus purpuratus
  • Transcription Factors
  • DNA

Associated data

  • GENBANK/U18784