CONSTITUTIVE FLOCCULATION IN SACCHAROMYCES-CEREVISIAE THROUGH OVEREXPRESSION OF THE GTS1 GENE, CODING FOR A GLO-TYPE ZN-FINGER-CONTAINING PROTEIN

The product of the cloned GTS1 gene is characterized by structural fea tures found in transcription factors. It contains one Zn-finger motif (CXXCX16CXXC) situated in the N-terminal end with a high degree of hom ology to the newly identified 'Glo' family of Zn-finger proteins (Irel and et al., 1994, EMBO J. 13, 3812-3821). The C-terminal end of the pr otein is characterized by poly (Ala-Gln) and poly-Gin stretches. Poly- Gin are part of trans-acting motifs in known transcription factors. Ov erexpression of the GTS1 gene results in constitutive flocculation. Wh ole cell electrophoretic mobility and hydrophobicity of GTS1 overexpre ssing cells was respectively lower and higher relative to control cell s. GTS1-induced flocculation is hardly sensitive to mannose in contras t to FLO1-determined flocculation. Overexpression of the GTS1 gene in a flo1 background does not abolish flocculation, suggesting that the F LO1 gene is not linked with the GTS1 gene in a 'flocculation pathway'. (C) 1997 by John Wiley & Sons, Ltd.