Molecular and General Genetics MGG

, Volume 253, Issue 4, pp 469–477

The Kluyveromyces lactis equivalent of casein kinase I is required for the transcription of the gene encoding the low-affinity glucose permease

  • J. Blaisonneau
  • H. Fukuhara
  • M. Wésolowski-Louvel
ORIGINAL PAPER

DOI: 10.1007/s004380050345

Cite this article as:
Blaisonneau, J., Fukuhara, H. & Wésolowski-Louvel, M. Mol Gen Genet (1997) 253: 469. doi:10.1007/s004380050345

Abstract

The RAG8 gene of Kluyveromyces lactis, which is one of the genes controlling the expression of the low-affinity carrier gene RAG1, has been cloned by in vivo complementation of the rag8 mutation. The sequence of Rag8p (535 amino acids), deduced from the nucleotide sequence of the cloned RAG8 gene, has been found to share a high degree of identity with the two casein kinases I of Saccharomyces cerevisiae, Yck1p and Yck2p, encoded by YCK1 and YCK2: the proteins are 65–66% identical overall and show 89–90% identity in the kinase domain. The finding that the RAG8 gene of K. lactis cloned in a centromeric vector was able to complement the growth defect of a yck1Δyck2tsmutant of S. cerevisiae strongly suggested that Rag8p is a casein kinase I. In contrast to the S. cerevisiae homologs, the RAG8 gene of K. lactis seems to be an essential single-copy gene, as shown by Southern blot experiments and the lethality of the rag8 null mutation. Northern blot analysis showed that the transcription of the RAG8 gene was higher on glucose media than in cells grown on a non-fermentable carbon source.

Key wordsKluyveromyces lactis  Casein kinase   Glucose transport  Transcriptional regulation

Copyright information

© Springer-Verlag Berlin Heidelberg 1997

Authors and Affiliations

  • J. Blaisonneau
    • 1
  • H. Fukuhara
    • 1
  • M. Wésolowski-Louvel
    • 2
  1. 1.Institut Curie, Section de Biologie, Bâtiment 110, Centre Universitaire, F-91405 Orsay Cédex, FranceFR
  2. 2.Centre de Génétique Cellulaire et Moléculaire, Université Claude Bernard, Bâtiment 405, 43, Boulevard du 11 Novembre 1918, F-69622 Villeurbanne Cédex, FranceFR