TTF, a gene encoding a novel small G protein, fuses to the lymphoma-associated LAZ3 gene by t(3;4) chromosomal translocation

Oncogene. 1995 Jun 1;10(11):2171-8.

Abstract

We have previously shown that the LAZ3/BCL6 gene encoding a potential transcription factor, is disrupted in B-diffuse large cell non-Hodgkin's lymphomas (NHL) with 3q27 chromosomal abnormalities involving the immunoglobulin (IG) genes. However, LAZ3 rearrangement also occurs in NHL bearing 3q27 translocations without involvement of the IG genes: for example the VAl cell line exhibits t(3;4)(q27;p11). In the present work we have used a RT-PCR method to detect and to sequence the LAZ3 mRNA products from the VAL cell line. We report that the consequence of the t(3;4) is the expression of a chimeric transcript of LAZ3 with a new gene encoding a small G-like protein, termed TTF (Translocation Three Four). Nucleotide sequence analysis of a 1.4 kb cDNA predicts that the TTF gene encodes a protein of 191 amino-acids similar to members of the RAS superfamily including HRAS (27% identical), RAB1A (30% identical) and RHO proteins: the human RAC1, RHOB and CDC42Hs proteins (respectively 43, 44 and 45% identical) and the yeast RHO2 protein (44% identical). Unlike most other small G proteins which are expressed ubiquitously, TTF was transcribed only in hemopoietic cells as a 2.2 kb transcript. TTF may define a new subgroup of RHO-like proteins.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Base Sequence
  • Chromosomes, Human, Pair 3
  • Chromosomes, Human, Pair 4
  • Cloning, Molecular*
  • DNA, Complementary
  • DNA-Binding Proteins / genetics*
  • GTP-Binding Proteins / genetics*
  • Humans
  • Molecular Sequence Data
  • Phylogeny
  • Proto-Oncogene Proteins c-bcl-6
  • RNA, Messenger / genetics
  • Sequence Homology, Amino Acid
  • Sequence Homology, Nucleic Acid
  • Transcription Factors / genetics*
  • Translocation, Genetic*
  • Tumor Cells, Cultured

Substances

  • BCL6 protein, human
  • DNA, Complementary
  • DNA-Binding Proteins
  • Proto-Oncogene Proteins c-bcl-6
  • RNA, Messenger
  • Transcription Factors
  • GTP-Binding Proteins

Associated data

  • GENBANK/Z35225
  • GENBANK/Z35227