The GTS1 gene, which contains a Gly-Thr repeat, affects the timing of budding and cell size of the yeast Saccharomyces cerevisiae.

Abstract

A gene with an open reading frame encoding a protein of 417 amino acid residues with a Gly-Thr repeat was isolated from the yeast Saccharomyces cerevisiae by using synthetic oligonucleotides encoding three Gly-Thr dimers as probes. The deduced amino acid sequence showed partial homology to the clock-affecting gene, per, of Drosophila melanogaster in the regions including the GT repeat. The function of the gene, named GTS1, was examined by characterizing the phenotypes of transformants with different copy numbers of the GTS1 gene produced either by inactivating the GTS1 gene by gene disruption (TMAgtsl) or by transformation with multicopy plasmid pPER119 (TMpGTS1). They grew at similar rates during the exponential growth phase, but the lag phases were shorter for TMAgtsl and longer for TMpGTS1 cells than that for the wild type. Analyses of their cell cycle parameters using synchronized cells revealed that the unbudding period changed as a function of gene dosage; that is, the periods of TMAgtsl and TMpGTS1 were about 20%o shorter and longer, respectively, than that of the wild-type. Another significant change in the transformants was detected in the distribution of the cell size. The mean cell volume of the TMAgtsl cells in the unbudded period (single cells) was 27% smaller than that of single wild-type cells, whereas that of single TMpGTS1 cells was 48% larger. Furthermore, in the temperature-sensitive cdc4 mutant, the GTS1 gene affected the timing of budding at the restrictive temperature. Thus, the GTS1 gene product appears to modulate the timing of budding to obtain an appropriate cell size independent of the DNA replication cycle.Among the genes known to affect biological clocks, the period gene (per) of Drosophila melanogaster (24, 37) and the frequency gene (frq) of Neurospora crassa (31) were the first to be isolated and sequenced. Characteristically, the amino acid sequences deduced from the nucleotide sequences of both genes each contained a Gly-Thr/Ser repeat which is shared by proteoglycans comprising a polysaccharide attachment site (31,37,43). Although the GT repeats are polymorphic in length and in sequence among the species of Drosophila (10,11,16,34,35,48,51), the presence of the GT repeat in the clockaffecting genes from evolutionarily remote species, Drosophila and Neurospora species, implies that this sequence plays an important role in most, if not all, clock-affecting proteins.The nature of per mutant phenotypes suggested that the gene product is an integral component of the circadian clock: mutations either shorten (pers), lengthen (per'), or abolish (per0) not only the period of circadian rhythms (19) but also the rhythm with a much shorter period during the male courtship song (26,52). Furthermore, the period of the circadian rhythm of D. melanogaster changes depending upon the gene dose (4,12,45

Ultradian oscillators of the circadian clock in <i>Saccharomyces</i> <i>cerevisiae</i>

“…Also, the period length of this oscillation was temperature independent, indicating a clock function [22]. In addition, a mutant in which the GTS1 gene, which has homology to period genes in other organisms [36] was deleted, produced a shortened period, about 20 min, with a destabilization in the amplitude of the oscillation every 11 h [34].…”

An ARL1 mutation affected autophagic cell death in yeast, causing a defect in central vacuole formation

“…Western blotting of carboxypeptidase Y (CPY) and alkaline phosphatase (ALP) was performed as described previously 43 using anti-CPY and anti-ALP antibodies (Molecular Probes, Eugene, OR, USA).…”

Interaction of the GTS1 gene product with glyceraldehyde‐ 3‐phosphate dehydrogenase 1 required for the maintenance of the metabolic oscillations of the yeast Saccharomyces cerevisiae

“…We subsequently found that the repeat was translated as an Ala-Gln repeat in the GTS1 product Gts1p [20], which is similar to the Gln-rich domain found in the clock-related protein Clock [21]. Although the structural basis of Gts1p as a clockrelated protein is obscure, mutations of GTS1 showed pleiotropic effects on yeast in a gene-dosage-dependent manner; these effects included the timing of budding and sporulation and the capacity for heat tolerance [19,22], all of which are known to be clock-related in other organisms (reviewed in [23,24]). Further, we found that the amplitudes and durations of the cyanide-induced ultradian oscillation changed significantly as a function of the GTS1 gene dosage, whereas the frequencies of oscillation did not vary very much among the stains tested [25].…”

“…The gene GTS1 was originally isolated from a yeast cDNA library with oligonucleotides encoding three Gly-Thr repeats which had been found in the clock-related gene period [18] and was thus named GTS1 [19]. We subsequently found that the repeat was translated as an Ala-Gln repeat in the GTS1 product Gts1p [20], which is similar to the Gln-rich domain found in the clock-related protein Clock [21].…”

“…(In this report, the term ÔcouplingÕ is used to refer to a state in which multiple oscillators fluctuate with the same periodicity irrespective of phase.) It should be added that a cellcycle-independent oscillation of energy metabolism with a short periodicity (20 min to 1 h) was observed under particular conditions in continuous cultures [17].The gene GTS1 was originally isolated from a yeast cDNA library with oligonucleotides encoding three Gly-Thr repeats which had been found in the clock-related gene period [18] and was thus named GTS1 [19]. We subsequently found that the repeat was translated as an Ala-Gln repeat in the GTS1 product Gts1p [20], which is similar to the Gln-rich domain found in the clock-related protein Clock [21].…”