Dissecting sensor functions in cell wall integrity signaling in Kluyveromyces lactis.
KlWSC1, KlWSC2/3 and KlMID2, which encode putative plasma membrane sensors for cell wall integrity signaling in Kluyveromyces lactis, were cloned and characterized. Double and triple deletion mutants show severe cell integrity defects, indicating overlapping functions. The Klwsc1 Klmid2 double deletion phenotype can be suppressed by overexpression of the downstream components KlROM2, KlPKC1 and KlBCK1. KlWsc1 sensor domain analyses showed that an amino-terminal elongation as well as an extension within the cytoplasmic domain are dispensable for function. Heterologous complementation by KlMID2 and KlWSC1 in Saccharomyces cerevisiae is only achieved upon overexpression. In contrast to ScMID2, ScWSC1 complements in K. lactis. Functional studies with chimeric Mid2 constructs indicate that species specificity is mainly conferred by the extracellular domain. Sensor-GFP fusions localize to the plasma membrane, with a cell cycle dependent distribution of KlWsc1-GFP. Both Wsc-type sensors concentrate in discrete spots within the plasma membrane.
Rodicio
Rosaura
R
Universität Osnabrück, Fachbereich Biologie/Chemie, AG Genetik, Barbarastr. 11, D-49076 Osnabrück, Germany.
Buchwald
Ulf
U
Schmitz
Hans-Peter
HP
Heinisch
Jürgen J
JJ
D000595:Amino Acid Sequence; D019677:Artificial Gene Fusion; D002462:Cell Membrane / Q000737:chemistry; D002473:Cell Wall / Q000502:physiology*; D003001:Cloning, Molecular; D005656:Fungal Proteins / Q000235:genetics* / Q000502:physiology*; D017353:Gene Deletion; D017930:Genes, Reporter; D005816:Genetic Complementation Test; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D007716:Kluyveromyces / Q000235:genetics / Q000502:physiology*; D008565:Membrane Proteins / Q000235:genetics / Q000502:physiology; D008856:Microscopy, Fluorescence; D008969:Molecular Sequence Data; D012441:Saccharomyces cerevisiae / Q000235:genetics; D016415:Sequence Alignment; D015398:Signal Transduction / Q000235:genetics* / Q000502:physiology*