The KlFUS1 gene is required for proper haploid mating and its expression is enhanced by the active form of the Galpha (Gpa1) subunit involved in the pheromone response pathway of the yeast Kluyveromyces lactis.
The Kluyveromyces lactis FUS1 gene was cloned, physically characterized and its role in the mating response pathway was determined. The gene encodes a putative membrane protein, whose structure shows a single membrane-spanning segment, a short extracellular amino-terminus and a long carboxy-terminus, located in the cytoplasmic side. The predicted primary structure of the protein shows a number of serine and threonine residues in the amino-terminus, which in analogy to Fus1p of Saccharomyces cerevisiae might be O-glycosylated. A fus1-GFP hybrid protein was tentatively located in the plasma membrane of dividing cells and upon activation of the pheromone response pathway, the protein seems to be relocated at the tip of elongated cells. KlFus1p is required for optimal conjugation of sexual partners and its expression is significantly enhanced by overexpression of both a constitutively active form of KlGpa1p, the G protein alpha subunit that triggers the mating response in this strain, and the KlSte12p transcription factor. Inactivation of the KlSte12 protein strongly reduces mating and affects KlFUS1 gene expression. The KlFUS1 gene has been deposited in the GenBank under accession number AF519444.
Lloret
Alejandro
A
Departamento de Genética Molecular, Instituto de Fisiologia Celular, Universidad Nacional Autónoma de México, Apartado Postal 70-242, 04510, D.F., Mexico, Mexico.
Saviñón-Tejeda
Alma
A
Ongay-Larios
Laura
L
Tenorio
Eda P
EP
Coria
Roberto
R
D000595:Amino Acid Sequence; D005656:Fungal Proteins / Q000235:genetics* / Q000378:metabolism; D015966:Gene Expression Regulation, Fungal; D006238:Haploidy; D020962:Heterotrimeric GTP-Binding Proteins / Q000378:metabolism*; D007716:Kluyveromyces / Q000235:genetics* / Q000502:physiology; D008565:Membrane Proteins; D008969:Molecular Sequence Data; D010675:Pheromones / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins; D017422:Sequence Analysis, DNA; D015398:Signal Transduction; D014158:Transcription, Genetic
C490024:FUS1 protein, S cerevisiae; D005656:Fungal Proteins; D008565:Membrane Proteins; D010675:Pheromones; D029701:Saccharomyces cerevisiae Proteins; D020962:Heterotrimeric GTP-Binding Proteins