PUBLICATION

Harbinger Transposons and an Ancient HARBI1 Gene Derived from a Transposase

Authors
Kapitonov, V.V., and Jurka, J.
ID
ZDB-PUB-040601-4
Date
2004
Source
DNA and cell biology   23(5): 311-324 (Journal)
Registered Authors
Kapitonov, Vladimir
Keywords
none
MeSH Terms
  • Amino Acid Motifs
  • Amino Acid Sequence
  • Animals
  • Anopheles/genetics
  • Conserved Sequence
  • DNA Transposable Elements/genetics*
  • Diatoms/genetics
  • Evolution, Molecular*
  • Gene Expression Regulation, Developmental
  • Humans
  • Insecta/genetics
  • Mice
  • Molecular Sequence Data
  • Rats
  • Takifugu/genetics
  • Transposases/genetics*
  • Vertebrates/genetics
  • Zebrafish/genetics
PubMed
15169610 Full text @ DNA Cell Biol.
Abstract
In this study we report main properties of Harbinger DNA transposons identified in protists, plants, insects, worms, and vertebrates. This is the first superfamily of eukaryotic DNA transposons where all autonomous transposons, even those that are hosted by species from different kingdoms, encode two proteins: a superfamily-specific transposase and a DNA-binding protein characterized by the presence of the conserved SANT/myb/trihelix motif. The last motif is known to be important for the DNA binding by different transcription regulators. Therefore, we suggest that this protein is necessary for coordinated expression of the Harbinger transposase. Although mammalian genomes are free of recognizable remnants of Harbingers, we identified a widely expressed HARBI1 gene encoding a 350-aa protein entirely derived from a Harbinger transposase some 450-500 million years ago. The HARBI1 proteins are conserved in humans, rats, mice, cows, pigs, chickens, frogs, and various bony fish, as well as other extremely important proteins, including RAG1 and RAG2. Conserved motifs detected in the Harbinger transposases are also well preserved in the HARBI1 proteins. Therefore, the HARBI1 proteins are expected to be nucleases important for functioning of bony vertebrates. We also found that the protein most similar to HARBI1 is encoded by an autonomous Harbinger 3_DR transposon that was transpositionally active in the zebrafish genome a few million years ago. Nonautonomous transposons derived from Harbinger3_DR are characterized by a striking preference for a 17-bp target site never seen previously in any other DNA transposon. Based on this observation, we suggest that the hypothetical HARBI1 nucleases are also characterized by a strong DNA-target specificity.
Genes / Markers
Figures
Expression
Phenotype
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
Antibodies
Orthology
Engineered Foreign Genes
Mapping