Journal of Molecular Evolution

, Volume 43, Issue 3, pp 170–178

Class III POU genes: Generation of homopolymeric amino acid repeats under GC pressure in mammals

  • Kenta Sumiyama
  • Keiko Washio-Watanabe
  • Naruya Saitou
  • Toshiyuki Hayakawa
  • Shintaroh Ueda
Article

DOI: 10.1007/BF02338824

Cite this article as:
Sumiyama, K., Washio-Watanabe, K., Saitou, N. et al. J Mol Evol (1996) 43: 170. doi:10.1007/BF02338824

Abstract

The class III POU transcription factor genes play an important role in the nervous system. Comparison of their entire amino acid sequences disclosed a remarkable feature of particular mammalian class III POU genes. Alanine, glycine, and proline repeats were present in the mammalian Brain-1 gene, whereas most of these repeats were absent in the nonmammalian homologue. The mammalian Brain-2 gene had alanine, glycine, proline, and glutamine repeats, which were missing in the nonmammalian homologue. The mammalian Scip gene had alanine, glycine, proline, and histidine repeats, but the nonmammalian homologue completely lacked these repeats. In contrast, the mammalian Brain-4 gene had no amino acid repeats like its nonmammalian homologue. The mammalian genes containing the characteristic amino acid repeats had another feature, higher GC content. We found a positive correlation between the GC content and the amino acid repeat ratio. Those amino acids were encoded by triplet codons with relatively high GC content. These results suggest that the GC pressure has facilitated generation of the homopolymeric amino acid repeats.

Key words

POU Human Brain-1 GC pressure Amino acid repeats 

Copyright information

© Springer-Verlag New York Inc 1996

Authors and Affiliations

  • Kenta Sumiyama
    • 1
  • Keiko Washio-Watanabe
    • 1
  • Naruya Saitou
    • 2
  • Toshiyuki Hayakawa
    • 1
  • Shintaroh Ueda
    • 1
  1. 1.Department of Biological Sciences, Graduate School of ScienceUniversity of TokyoBunkyo-Ku, TokyoJapan
  2. 2.Laboratory of Evolutionary GeneticsNational Institute of GeneticsMishimaJapan