Oligomerization of the ABL tyrosine kinase by the Ets protein TEL in human leukemia

Mol Cell Biol. 1996 Aug;16(8):4107-16. doi: 10.1128/MCB.16.8.4107.

Abstract

TEL is a member of the Ets family of transcription factors which are frequently rearranged in human leukemia. The mechanism of TEL-mediated transformation, however, is unknown. We report the cloning and characterization of a chromosomal translocation associated with acute myeloid leukemia which fuses TEL to the ABL tyrosine kinase. The TEL-ABL fusion confers growth factor-independent growth to the marine hematopoietic cell line Ba/F3 and transforms Rat-1 fibroblasts and primary murine bone marrow cells. TEL-ABL is constitutively tyrosine phosphorylated and localizes to the cytoskeleton. A TEL-ABL mutant containing an ABL kinase-inactivating mutation is not constitutively phosphorylated and is nontransforming but retains cytoskeletal localization. However, constitutive phosphorylation, cytoskeletal localization, and transformation are all dependent upon a highly conserved region of TEL termed the helix-loop-helix (HLH) domain. TEL-ABL formed HLH-dependent homo-oligomers in vitro, a process critical for tyrosine kinase activation. These experiments suggest that oligomerization of TEL-ABL mediated by the TEL HLH domain is required for tyrosine kinase activation, cytoskeletal localization, and transformation. These data also suggest that oligomerization of Ets proteins through the highly conserved HLH domain may represent a previously unrecognized phenomenon.

Publication types

  • Case Reports
  • Comparative Study
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Aged
  • Aged, 80 and over
  • Amino Acid Sequence
  • Base Sequence
  • Chromosome Mapping
  • Chromosomes, Human, Pair 12
  • Cytoskeletal Proteins / metabolism
  • DNA Primers / chemistry
  • DNA-Binding Proteins / metabolism*
  • Gene Expression Regulation, Neoplastic
  • Helix-Loop-Helix Motifs
  • Humans
  • Leukemia, Myeloid / metabolism*
  • Male
  • Molecular Sequence Data
  • Phosphoproteins / metabolism
  • Protein Binding
  • Proto-Oncogene Proteins c-abl / metabolism*
  • Proto-Oncogene Proteins c-ets
  • RNA, Messenger / genetics
  • RNA, Neoplasm / genetics
  • Recombinant Fusion Proteins
  • Repressor Proteins*
  • Sequence Alignment
  • Sequence Homology, Amino Acid
  • Transcription Factors / metabolism*
  • Translocation, Genetic

Substances

  • Cytoskeletal Proteins
  • DNA Primers
  • DNA-Binding Proteins
  • ETS translocation variant 6 protein
  • Phosphoproteins
  • Proto-Oncogene Proteins c-ets
  • RNA, Messenger
  • RNA, Neoplasm
  • Recombinant Fusion Proteins
  • Repressor Proteins
  • Transcription Factors
  • Proto-Oncogene Proteins c-abl