HTLV-I and HTLV-II Tax: differences in induction of micronuclei in cells and transcriptional activation of viral LTRs

Virology. 1996 Mar 1;217(1):373-9. doi: 10.1006/viro.1996.0126.


Human T-cell leukemia virus (HTLV) types I and II are highly related viruses that differ in disease manifestations. HTLV-I has been linked unmistakably to adult T-cell leukemia-lymphoma. On the other hand, there is little evidence that prior infection with HTLV-II increases risk for lymphoproliferative disorders. Both viruses encode homologous transcriptional-activating proteins (respectively designated as Tax1 and Tax2) which have been suggested to be important mediators of viral pathogenesis. Previously, we reported that Tax1 is a potent inducer of micronuclei formation in cells. Here, we present evidence that Tax2 lacks micronuclei inductive ability. We contrast this phenotypic difference between Tax1 and Tax2 at the cellular level with their similarities at the molecular level in transcriptional activation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Cell Line
  • Gene Products, tax / chemistry
  • Gene Products, tax / genetics
  • Gene Products, tax / physiology*
  • Human T-lymphotropic virus 1 / genetics
  • Human T-lymphotropic virus 1 / physiology*
  • Human T-lymphotropic virus 2 / genetics
  • Human T-lymphotropic virus 2 / physiology*
  • Humans
  • Micronuclei, Chromosome-Defective / virology*
  • Molecular Sequence Data
  • Mutation
  • Repetitive Sequences, Nucleic Acid / genetics*
  • Sequence Homology, Amino Acid
  • Transcriptional Activation*


  • Gene Products, tax