Yeast Sequencing Report Isolation of GCR1, a major transcription factor of glycolytic genes in Saccharomyces cerevisiae, from Kluyveromyces lactis Robin Haw, Aruna Devi Yarragudi and Hiroshi Uemura* Department of Molecular Biology, National Institute of Bioscience and Human Technology, Higashi 1-1, Tsukuba, Ibaraki, 305-8566 Japan * Correspondence to: H. Uemura, Department of Molecular Biology, National Institute of Bioscience and Human Technology, Higashi 1-1, Tsukuba, Ibaraki, 305-8566 Japan. E-mail: uemura@nibh.go.jp Received: 20 September 2000 Accepted: 29 December 2000 Abstract To study the function of GCR1, a gene involved in the expression of glycolytic genes in Saccharomyces cerevisiae,a Kluyveromyces lactis gene that complements the growth defect of a S. cerevisiae Dgcr1 mutant was isolated. Introduction of this gene into the Dgcr1 mutant also restored the activities of glycolytic enzymes. DNA sequencing of KlGCR1 predicted an open reading frame of a 767 amino acid protein with an overall identity of 33% and similarity of 48% to Gcr1p from S. cerevisiae. Its DDBJ/EMBL/ GenBank Accession No. is AB046391. Copyright # 2001 John Wiley & Sons, Ltd. Keywords: transcription; glycolysis; GCR1; Kluyveromyces lactis; Saccharomyces cerevisiae Introduction The budding yeasts Saccharomyces cerevisiae and Kluyveromyces lactis are closely related evolutiona- rily. The glycolytic pathway is a major metabolic route in budding yeast and the glycolytic enzyme genes are highly expressed (Fraenkel, 1982). Within the UAS elements of the glycolytic genes are the binding sites for Rap1p and Gcr1p (Huie et al., 1992). These two DNA-binding proteins coordi- nately regulate the expression of glycolytic enzyme genes (reviewed by Chambers et al., 1995). Since Rap1p is capable of carrying out many diverse cellular functions, such as activation and repression of transcription depending on the sequence context of its binding site, it has been suggested that its function may be determined by the interaction with other regulatory proteins (Baker, 1991; Shore, 1994). The most likely role of Rap1p at glycolytic promoters is to facilitate the binding of Gcr1p (Drazinic et al., 1996; Uemura et al., 1997; Lopez et al., 1998). In addition to Rap1p, Gcr1p also acts with Gcr2p to mediate high levels of glycolytic gene expression. Uemura and Jigami (1992) presented genetic evidence for a physical interaction between Gcr2p and Gcr1p and postulated that Gcr2p probably functions as a co-activator in the Gcr1p–Gcr2p complex (Uemura and Jigami, 1995). Consistent with this view, similar profiles of reduc- tion of the levels of most glycolytic enzymes were observed in gcr1 and gcr2 mutants (Uemura and Fraenkel, 1990). Gcr1p is a 785 amino acid protein with three hydrophobic domains that are separated by hydro- philic residues (Uemura and Suzuki, 1995). The N-terminal region contains the transcriptional acti- vation domain and a region that interacts with another molecule of Gcr1p or Gcr2p (Uemura and Jigami, 1995; Deminoff et al., 1995). In the central linker domain, 11 serine–proline sequences and one threonine–proline sequence are clustered (Uemura and Suzuki, 1995) and it was predicted that the hyperphosphorylation of serine is important for the activation function of Gcr1p (Zeng et al., 1997). The DNA binding activity is confined to the C- terminus of the protein (Huie et al., 1992). However, the fine mechanisms by which Gcr1p exerts its function(s) remain to be elucidated. It is difficult to draw inferences from the primary sequence as to which regions may be important for function, because Gcr1p (and Gcr2p) display no Yeast Yeast 2001; 18: 729–735. DOI: 10.1002 /yea.718 Copyright # 2001 John Wiley & Sons, Ltd.