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Profiling of Permethylated Mucin O-glycans Using Matrix-assisted Laser Desorption/Ionization Time-of-flight Mass Spectrometry
Published on: June 20, 2025
Mucins, osmosensors in eukaryotic cells?
Eulàlia de Nadal1, Francisco X Real, Francesc Posas
1Cell Signaling Unit, Departament de Ciències Experimentals i de la Salut, Universitat Pompeu Fabra (UPF), Spain.
Trends in Cell Biology
|November 6, 2007
Summary
Yeast Msb2 and Hkr1 proteins, similar to mammalian mucins, may sense high extracellular osmolarity. These proteins activate the high osmolarity glycerol (HOG) pathway, crucial for cellular adaptation to osmotic stress.
Area of Science:
- Cellular biology
- Molecular mechanisms of stress response
- Eukaryotic osmoregulation
Background:
- Mechanisms for sensing extracellular high osmolarity in eukaryotes are poorly understood.
- Yeast Msb2 and Hkr1 proteins share similarities with mammalian mucins.
- Osmotic stress adaptation involves complex signaling pathways.
Purpose of the Study:
- To investigate the role of yeast Msb2 and Hkr1 in sensing extracellular osmostress.
- To explore the involvement of these proteins in activating the high osmolarity glycerol (HOG) pathway.
- To assess the potential of transmembrane mucins in sensing osmotic imbalances in higher eukaryotes.
Main Methods:
- Analysis of yeast osmostress response pathways.
- Investigating the function of Msb2 and Hkr1 proteins.
- Comparative analysis with mammalian mucin signaling.
Main Results:
- Yeast Msb2 and Hkr1 are identified as strong candidates for osmosensing.
- These proteins are involved in activating the HOG stress-activated protein kinase pathway.
- Evidence suggests a conserved role for mucin-like proteins in osmostress adaptation.
Conclusions:
- Msb2 and Hkr1 play a key role in yeast osmosensing and HOG pathway activation.
- Transmembrane mucins represent a conserved mechanism for detecting osmotic changes.
- Further research into mammalian mucins could reveal their role in osmotic homeostasis.
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