DP-2, a heterodimeric partner of E2F: identification and characterization of DP-2 proteins expressed in vivo

Proc Natl Acad Sci U S A. 1996 Jul 23;93(15):7594-9. doi: 10.1073/pnas.93.15.7594.

Abstract

E2F is a heterodimeric transcription factor that regulates the expression of genes at the G1/S boundary and is composed of two related but distinct families of proteins, E2F and DP. E2F/DP heterodimers form complexes with the retinoblastoma (Rb) protein, the Rb-related proteins p107 and p130, and cyclins/cdks in a cell cycle-dependent fashion in vivo. E2F is encoded by at least five closely related genes, E2F-1 through -5. Here we report studies of DP-2, the second member of the DP family of genes. Our results indicate that (i) DP-2 encodes at least five distinct mRNAs, (ii) a site of alternative splicing occurs within the 5' untranslated region of DP-2 mRNA, (iii) at least three DP-2-related proteins (of 55, 48, and 43 kDa) are expressed in vivo, (iv) each of these proteins is phosphorylated, and (v) one DP-2 protein (43 kDa) carries a truncated amino terminus. Our data also strongly suggest that the 55-kDa DP-2-related protein is a novel DP-2 isoform that results from alternative splicing. Thus, we conclude that DP-2 encodes a set of structurally, and perhaps functionally, distinct proteins in vivo.

Publication types

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

MeSH terms

  • Alternative Splicing
  • Amino Acid Sequence
  • Animals
  • Base Sequence
  • Carrier Proteins*
  • Cell Cycle Proteins*
  • Cell Line
  • Chlorocebus aethiops
  • DNA-Binding Proteins / biosynthesis*
  • DNA-Binding Proteins / isolation & purification
  • DNA-Binding Proteins / metabolism
  • E2F Transcription Factors
  • E2F1 Transcription Factor
  • Electrophoresis, Polyacrylamide Gel
  • Helix-Loop-Helix Motifs
  • Methionine / metabolism
  • Molecular Sequence Data
  • Molecular Weight
  • Multigene Family
  • Phosphates / metabolism
  • Phosphoproteins / isolation & purification
  • Phosphoproteins / metabolism
  • Phosphorus Radioisotopes
  • Phosphorylation
  • RNA, Messenger / biosynthesis
  • Recombinant Proteins / biosynthesis
  • Recombinant Proteins / isolation & purification
  • Recombinant Proteins / metabolism
  • Retinoblastoma Protein / metabolism
  • Retinoblastoma-Binding Protein 1
  • Saccharomyces cerevisiae
  • Sequence Homology, Nucleic Acid
  • Sulfur Radioisotopes
  • Transcription Factor DP1
  • Transcription Factors / biosynthesis*
  • Transcription Factors / isolation & purification
  • Transcription Factors / metabolism*
  • Transcription, Genetic
  • Transfection

Substances

  • Carrier Proteins
  • Cell Cycle Proteins
  • DNA-Binding Proteins
  • E2F Transcription Factors
  • E2F1 Transcription Factor
  • Phosphates
  • Phosphoproteins
  • Phosphorus Radioisotopes
  • RNA, Messenger
  • Recombinant Proteins
  • Retinoblastoma Protein
  • Retinoblastoma-Binding Protein 1
  • Sulfur Radioisotopes
  • Transcription Factor DP1
  • Transcription Factors
  • Methionine

Associated data

  • GENBANK/U35117