title: The serine/threonine phosphatase DhSIT4 modulates cell cycle, salt tolerance and cell wall integrity in halo tolerant yeast Debaryomyces hansenii.
abstract: The highly conserved family of Phosphoprotein phosphatases (PPP) regulates several major physiological processes in yeast. However, very little is known about the PPP orthologs from the yeast species inhabiting extreme environmental niches. In the present study we have identified DhSIT4, a member of PPP6 class of serine threonine phosphatases from the halotolerant yeast Debaryomyces hansenii. Deletion of DhSIT4 in D. hansenii was not lethal but the mutant exhibited reduced growth due to its effect on the cell cycle. The knock out mutant Dhsit4Δ showed sensitivity towards Li+, Na+and cell wall damaging agents. The expression of DhSit4p rescued salt, caffeine and calcofluor white sensitivity of Dhmpk1Δ strain and thereby indicating a genetic interaction of this phosphatase with the cell wall integrity pathway in this species. Our study also demonstrated the antagonistic roles of DhSit4p and DhPpz1p in maintaining the cell cycle and ion homeostasis in D. hansenii.
authors.affiliation: CSIR-Institute of Microbial Technology, Chandigarh 160036, India.
authors.forename: Srishti
authors.initials: S
authors.lastname: Chawla
authors.affiliation: CSIR-Institute of Microbial Technology, Chandigarh 160036, India.
authors.forename: Debasree
authors.initials: D
authors.lastname: Kundu
authors.affiliation: CSIR-Institute of Microbial Technology, Chandigarh 160036, India.
authors.forename: Anmoldeep
authors.initials: A
authors.lastname: Randhawa
authors.affiliation: School of Life Sciences, Jawaharlal Nehru University, New Delhi 110067. Electronic address: akmondal@mail.jnu.ac.in.
authors.forename: Alok K
authors.initials: AK
authors.lastname: Mondal
mesh_terms: D002453:Cell Cycle; D002473:Cell Wall / Q000378:metabolism; D005656:Fungal Proteins / Q000378:metabolism*; D010749:Phosphoprotein Phosphatases / Q000378:metabolism; D054648:Protein Phosphatase 2 / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000378:metabolism*; D004718:Saccharomycetales / Q000145:classification / Q000166:cytology* / Q000201:enzymology* / Q000502:physiology
chemical_list: D005656:Fungal Proteins; D029701:Saccharomyces cerevisiae Proteins; D010749:Phosphoprotein Phosphatases; D054648:Protein Phosphatase 2; C104343:SIT4 protein, S cerevisiae
keywords: Debaryomyces hansenii; Halotolerance; PPP phosphatase; SIT4; Yeast