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Stress sensitivity of a fission yeast strain lacking histidine kinases is rescued by the ectopic expression of Chk1 from Candida albicans

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ABSTRACT

The development of new drugs against the pathogenic yeast Candida albicans is compelling and the evolution of relevant bioassays is important to achieve this goal. Promising drug targets are proteins that lack human counterparts which are true for the His-to-Asp phosphorelay signal transduction systems, important for stress sensing in bacteria, fungi, and plants. In the pathogenic yeast, Candida albicans, the CaChk1 histidine kinase is a trigger of the pathway that leads to a switch from yeast to hyphal growth necessary for invasion. Intriguingly, the model yeast Schizosaccharomyces pombe has a similar phosphorelay system, with three histidine kinases named Mak1, Mak2, and Mak3, which are important for the prevention of aberrant mating and sporulation on rich media. This study uncovered distinct functions for the three histidine kinases; Mak1 alone or Mak2 and Mak3 together were sufficient for the repression of the meiotic cycle when nutrients were available. Moreover, strains lacking histidine kinase genes were sensitive to various types of stress conditions in an auxotrophic strain background, while the stress sensitivity was lost in prototrophic strains. Finally, the stress sensitivity of a S. pombe strain that lacks endogenous histidine kinases could be complemented by the ectopic expression of the CaChk1 histidine kinase from C. albicans. This finding opens up for the possibility to perform a drug screen with a biological read-out in S. pombe to find inhibitors of CaChk1.

Electronic supplementary material: The online version of this article (doi:10.1007/s00294-016-0644-9) contains supplementary material, which is available to authorized users.

No MeSH data available.


Schematic picture of the histidine kinases from S. cerevisiae, S. pombe, and C. albicans. Organisation of relevant domains found using InterPro (http://www.ebi.ac.uk/interpro/) in the histidine kinases from S. cerevisiae, S. pombe, and C. albicans. Response regulator receiver domain (blue), histidine kinase ATPase domain (purple), GAF domain (green), PAS/PAC domain (red), Ser/Thr kinase domain (orange), and HAMP domain (dark blue)
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Fig1: Schematic picture of the histidine kinases from S. cerevisiae, S. pombe, and C. albicans. Organisation of relevant domains found using InterPro (http://www.ebi.ac.uk/interpro/) in the histidine kinases from S. cerevisiae, S. pombe, and C. albicans. Response regulator receiver domain (blue), histidine kinase ATPase domain (purple), GAF domain (green), PAS/PAC domain (red), Ser/Thr kinase domain (orange), and HAMP domain (dark blue)

Mentions: Schizosaccharomyces pombe has three HKs, that all have the conserved histidine kinase ATPase domain (Fig. 1, purple) and a conserved response regulator domain (Fig. 1, blue). Overall, there is a much greater similarity between Mak2 and Mak3 as compared with Mak1. The former are larger proteins with several domains not found in Mak1, in particular, a GAF domain and a serine/threonine kinase domain. To elucidate whether the three HKs from S. pombe have redundant functions, precise gene deletions of the three HKs are preferred. The previous studies on strains lacking the HKs replaced part of the genes by the introduction of marker genes leaving the 5′ and the 3′ ends present in the genome (Aoyama et al. 2001; Buck et al. 2001). To get precise gene deletions, we constructed our own S. pombe strains lacking one of the three HKs by replacing the genes with antibiotic resistance markers; mak1+ was replaced by kanMX6, mak2+ was replaced by natMX6, and finally, mak3+ was replaced by hygMX6. We also generated double knockout strains in all combinations, as well as a triple knockout strain, by crossing.Fig. 1


Stress sensitivity of a fission yeast strain lacking histidine kinases is rescued by the ectopic expression of Chk1 from Candida albicans
Schematic picture of the histidine kinases from S. cerevisiae, S. pombe, and C. albicans. Organisation of relevant domains found using InterPro (http://www.ebi.ac.uk/interpro/) in the histidine kinases from S. cerevisiae, S. pombe, and C. albicans. Response regulator receiver domain (blue), histidine kinase ATPase domain (purple), GAF domain (green), PAS/PAC domain (red), Ser/Thr kinase domain (orange), and HAMP domain (dark blue)
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

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getmorefigures.php?uid=PMC5383687&req=5

Fig1: Schematic picture of the histidine kinases from S. cerevisiae, S. pombe, and C. albicans. Organisation of relevant domains found using InterPro (http://www.ebi.ac.uk/interpro/) in the histidine kinases from S. cerevisiae, S. pombe, and C. albicans. Response regulator receiver domain (blue), histidine kinase ATPase domain (purple), GAF domain (green), PAS/PAC domain (red), Ser/Thr kinase domain (orange), and HAMP domain (dark blue)
Mentions: Schizosaccharomyces pombe has three HKs, that all have the conserved histidine kinase ATPase domain (Fig. 1, purple) and a conserved response regulator domain (Fig. 1, blue). Overall, there is a much greater similarity between Mak2 and Mak3 as compared with Mak1. The former are larger proteins with several domains not found in Mak1, in particular, a GAF domain and a serine/threonine kinase domain. To elucidate whether the three HKs from S. pombe have redundant functions, precise gene deletions of the three HKs are preferred. The previous studies on strains lacking the HKs replaced part of the genes by the introduction of marker genes leaving the 5′ and the 3′ ends present in the genome (Aoyama et al. 2001; Buck et al. 2001). To get precise gene deletions, we constructed our own S. pombe strains lacking one of the three HKs by replacing the genes with antibiotic resistance markers; mak1+ was replaced by kanMX6, mak2+ was replaced by natMX6, and finally, mak3+ was replaced by hygMX6. We also generated double knockout strains in all combinations, as well as a triple knockout strain, by crossing.Fig. 1

View Article: PubMed Central - PubMed

ABSTRACT

The development of new drugs against the pathogenic yeast Candida albicans is compelling and the evolution of relevant bioassays is important to achieve this goal. Promising drug targets are proteins that lack human counterparts which are true for the His-to-Asp phosphorelay signal transduction systems, important for stress sensing in bacteria, fungi, and plants. In the pathogenic yeast, Candida albicans, the CaChk1 histidine kinase is a trigger of the pathway that leads to a switch from yeast to hyphal growth necessary for invasion. Intriguingly, the model yeast Schizosaccharomyces pombe has a similar phosphorelay system, with three histidine kinases named Mak1, Mak2, and Mak3, which are important for the prevention of aberrant mating and sporulation on rich media. This study uncovered distinct functions for the three histidine kinases; Mak1 alone or Mak2 and Mak3 together were sufficient for the repression of the meiotic cycle when nutrients were available. Moreover, strains lacking histidine kinase genes were sensitive to various types of stress conditions in an auxotrophic strain background, while the stress sensitivity was lost in prototrophic strains. Finally, the stress sensitivity of a S. pombe strain that lacks endogenous histidine kinases could be complemented by the ectopic expression of the CaChk1 histidine kinase from C. albicans. This finding opens up for the possibility to perform a drug screen with a biological read-out in S. pombe to find inhibitors of CaChk1.

Electronic supplementary material: The online version of this article (doi:10.1007/s00294-016-0644-9) contains supplementary material, which is available to authorized users.

No MeSH data available.