Binding of the Extracellular Eight-Cysteine Motif of Opy2 to the Putative Osmosensor Msb2 Is Essential for Activation of the Yeast High-Osmolarity Glycerol Pathway

@article{Yamamoto2015BindingOT,
  title={Binding of the Extracellular Eight-Cysteine Motif of Opy2 to the Putative Osmosensor Msb2 Is Essential for Activation of the Yeast High-Osmolarity Glycerol Pathway},
  author={Katsuyoshi Yamamoto and Kazuo Tatebayashi and Haruo Saito},
  journal={Molecular and Cellular Biology},
  year={2015},
  volume={36},
  pages={475 - 487}
}
ABSTRACT To adapt to environmental high osmolarity, the budding yeast Saccharomyces cerevisiae activates the Hog1 mitogen-activated protein kinase, which regulates diverse osmoadaptive responses. Hog1 is activated through the high-osmolarity glycerol (HOG) pathway, which consists of independent upstream signaling routes termed the SLN1 branch and the SHO1 branch. Here, we report that the extracellular cysteine-rich (CR) domain of the transmembrane-anchor protein Opy2 binds to the Hkr1-Msb2… 
Scaffold Protein Ahk1, Which Associates with Hkr1, Sho1, Ste11, and Pbs2, Inhibits Cross Talk Signaling from the Hkr1 Osmosensor to the Kss1 Mitogen-Activated Protein Kinase
TLDR
Ahk1 is a scaffold protein in the HKR1 subbranch and prevents incorrect signal flow from Hkr1 to Kss1, which is a large, highly glycosylated, single-path transmembrane protein that is a putative osmosensor in one of the Hog1 upstream pathways termed the H KR1Subbranch.
Activation of the Hog1 MAPK by the Ssk2/Ssk22 MAP3Ks, in the absence of the osmosensors, is not sufficient to trigger osmostress adaptation in Saccharomyces cerevisiae
TLDR
It is demonstrated that the uncoupling of the known sensors of both branches of the HOG pathway at the level of Ssk1 and Ste11 impairs cell growth in hyperosmotic medium, and indicates that Hog1 phosphorylation by noncanonical upstream mechanisms is not sufficient to trigger a protective response to hyperOSmotic stress.
Proteins That Interact with the Mucin-Type Glycoprotein Msb2p Include Regulators of the Actin Cytoskeleton
TLDR
This study identifies proteins that connect a signalling mucin to diverse cellular processes and may provide insight into new aspects of mucin function.
Osmostress enhances activating phosphorylation of Hog1 MAP kinase by mono‐phosphorylated Pbs2 MAP2K
TLDR
It is reported that theMAP3K Ste11 phosphorylates only one activating phosphorylation site in Pbs2, whereas the MAP3Ks Ssk2/Ssk22 can phosphorylate both Ser‐514 and Thr‐518 under optimal osmostress conditions.
Functions for Cdc42p BEM adaptors in regulating a differentiation-type MAP kinase pathway
TLDR
Genetic suppression tests showed that Bem4p and Bem1p regulate the fMAPK pathway in an ordered sequence, demonstrating unique and sequential functions for Rho GTPase adaptors in regulating MAPK pathways.
Functions for Cdc42p BEM Adaptors in Regulating a Differentiation-Type MAP Kinase Pathway
TLDR
Comparing Cdc42p-dependent MAPK pathways showed that the fMAPK pathway had slow activation kinetics compared to the mating and HOG pathways, and demonstrates unique and sequential functions for Rho GTPase adaptors in regulatingMAPK pathways.
Genetic dissection of the signaling pathway required for the cell wall integrity checkpoint
TLDR
Genetic evidence that signaling from the cell surface regulates the downstream transcriptional machinery to activate the cell wall integrity checkpoint is provided, suggesting an order to these signaling pathways.
Spatiotemporal Control of Pathway Sensors and Cross-Pathway Feedback Regulate a Cell Differentiation MAPK Pathway in Yeast
TLDR
Spatial and temporal regulation of pathway sensors, and cross-pathway feedback, regulate a MAPK pathway that controls a cell differentiation response in yeast.
Spatiotemporal control of pathway sensors and cross-pathway feedback regulate a differentiation MAPK pathway in yeast.
TLDR
Spatial and temporal regulation of pathway sensors, and cross-pathway regulation, control a MAPK pathway that regulates cell differentiation in yeast.
Opposing signaling pathways regulate morphology in response to temperature in the fungal pathogen Histoplasma capsulatum
TLDR
The first genetic screen to identify genes required for hyphal growth of H. capsulatum at RT is performed and finds that disruption of the signaling mucin MSB2 results in a yeast-locked phenotype, indicating that the Ryp and Msb2 circuits antagonize each other in a temperature-dependent manner.
...
1
2
...

References

SHOWING 1-10 OF 59 REFERENCES
Binding the atypical RA domain of Ste50p to the unfolded Opy2p cytoplasmic tail is essential for the high-osmolarity glycerol pathway.
TLDR
The solution structure of the Ste50p-RA (Ras association) domain is determined, and it shows an atypical RA fold lacking the beta1 and beta2 strands of the canonical motif, suggesting a multivalent interaction of these proteins as a crucial point of control of the HOG pathway.
Transmembrane mucins Hkr1 and Msb2 are putative osmosensors in the SHO1 branch of yeast HOG pathway
TLDR
It is shown that the mucin‐like transmembrane proteins Hkr1 and Msb2 are the potential osmosensors for the SHO1 branch of the HOG pathway, and that these proteins are the most upstream elements known so far in the SHo1 branch.
Osmosensing and scaffolding functions of the oligomeric four-transmembrane domain osmosensor Sho1
TLDR
It is demonstrated that the four-transmembrane (TM) domain protein Sho1 is an osmosensor in the HKR1 sub-branch of the HOG pathway, which coordinates adaptation to high osmolarity conditions.
A Third Osmosensing Branch in Saccharomyces cerevisiae Requires the Msb2 Protein and Functions in Parallel with the Sho1 Branch
TLDR
Two Saccharomyces cerevisiae plasma membrane-spanning proteins, Sho1 and Sln1, function during increased osmolarity to activate a mitogen-activated protein (MAP) kinase cascade, and it is suggested that Msb2 is partially redundant with the Sho1 osmosensing branch for the activation of Ste11.
Requirement of STE50 for Osmostress-Induced Activation of the STE11 Mitogen-Activated Protein Kinase Kinase Kinase in the High-Osmolarity Glycerol Response Pathway
TLDR
It was concluded that STE50 fulfills an essential role in the activation of the high-osmolarity glycerol response pathway by acting as an integral subunit of the STE11 MAPKKK.
Yeast Osmosensors Hkr1 and Msb2 Activate the Hog1 MAPK Cascade by Different Mechanisms
TLDR
A unique mechanism by which only one of these “redundant” pathways integrates osmotic stress signals withregulation of the actin cytoskeleton is revealed, which may enable differential regulation of these two proteins and provide a mechanism through Msb2 to connect regulation of the cytos skeleton with the response to osmatic stress.
Adaptor functions of Cdc42, Ste50, and Sho1 in the yeast osmoregulatory HOG MAPK pathway
TLDR
It is found that Cdc42, in addition to binding and activating the PAK‐like kinases Ste20 and Cla4, binds to the Ste11–Ste50 complex to bring activated Ste20/Cla4 to their substrate Ste11, then to Pbs2, to act as adaptor proteins that control the flow of the osmostress signal.
...
1
2
3
4
5
...