Related Experiment Video
Updated: Aug 11, 2026
04:36
Assay for Adhesion and Agar Invasion in S. cerevisiae
Published on: November 8, 2006
Two-component signal transduction in human fungal pathogens
Michael Kruppa1, Richard Calderone
1Department of Microbiology & Immunology, Georgetown University Medical Center, Washington DC 20057, USA.
FEMS Yeast Research
|February 21, 2006
Summary
The HOG1 MAP kinase pathway helps fungi adapt to environmental stress. This pathway regulates crucial functions like cell wall biosynthesis and virulence in pathogens such as Candida albicans.
Area of Science:
- Microbiology
- Molecular Biology
- Biochemistry
Background:
- Signal transduction pathways are critical for cellular adaptation to environmental stress.
- The HOG1 MAP kinase pathway is a well-studied mechanism for osmostress adaptation in Saccharomyces cerevisiae.
- The HOG1 pathway's role in adaptation has been observed in human pathogens like Candida albicans, Aspergillus fumigatus, and Cryptococcus neoformans.
Purpose of the Study:
- To investigate the functions of the HOG1 MAP kinase pathway in pathogenic fungi.
- To identify two-component signal proteins regulating the HOG1 pathway in Candida albicans.
- To understand how HOG1 pathway regulation contributes to fungal adaptation and virulence.
Main Methods:
- Comparative analysis of HOG1 pathway components across different fungal species.
- Identification and characterization of two-component signal proteins in Candida albicans.
- Functional studies assessing the impact of HOG1 pathway regulation on cellular processes.
Main Results:
- The HOG1 pathway is conserved across fungal pathogens but mediates distinct adaptive functions.
- Two-component signal proteins regulating HOG1 were identified in Candida albicans.
- These proteins influence cell wall biosynthesis, osmotic/oxidant adaptation, morphogenesis, and virulence.
Conclusions:
- The HOG1 MAP kinase pathway is essential for fungal adaptation to diverse environmental challenges.
- Regulation of HOG1 by two-component systems is a key mechanism for controlling virulence and host interactions in Candida albicans.
Related Concept Videos
01:28Yeast Signaling
Yeasts are single-celled organisms, but unlike bacteria, they are eukaryotes (cells with a nucleus). Cell signaling in yeast is similar to signaling in other eukaryotic cells. A ligand, such as a protein or a small molecule released from a yeast cell, attaches to a receptor on the cell surface. The binding stimulates second-messenger kinases to activate or inactivate transcription factors that further regulate gene expression. Many of the yeast intracellular signaling cascades have similar...
01:15Antifungal Agents
Amphotericin B is a broad-spectrum antifungal agent that exploits structural differences between fungal and mammalian cell membranes. Its amphipathic structure—featuring a hydrophobic polyene-lactone ring and a hydrophilic region containing mycosamine and carboxylic acid groups—enables selective binding to ergosterol, a sterol predominantly found in fungal plasma membranes. This selective interaction underlies the drug’s antifungal activity, although weak binding to cholesterol contributes to...
01:19Interactions Between Signaling Pathways
Signaling cascades usually lack linearity. Multiple pathways interact and regulate one another, allowing cells to integrate and respond to diverse environmental stimuli.
Convergence and divergence, and cross-talk between signaling pathways
Two distinct signaling pathways can converge on a single functional unit, which may either be a single protein or a complex of proteins. The response is either functionally distinct or synergistic between the two pathways but different from the response...
Convergence and divergence, and cross-talk between signaling pathways
Two distinct signaling pathways can converge on a single functional unit, which may either be a single protein or a complex of proteins. The response is either functionally distinct or synergistic between the two pathways but different from the response...
01:28Regulation of Bacterial Virulence
Pathogenic bacteria employ a range of regulatory mechanisms to modulate the expression of virulence genes in response to environmental and host-derived signals. These mechanisms ensure that virulence factors are expressed only under favorable conditions, thereby optimizing infection and survival strategies.Mechanisms of Virulence RegulationKey regulatory strategies include:Two-Component Systems: These consist of a membrane-bound sensor kinase and a cytoplasmic response regulator. Environmental...
01:22Amplifying Signals via Enzymatic Cascade
When a ligand binds to a cell-surface receptor, the receptor's intracellular domain changes shape, which may either activate its enzyme function or allow its binding to other molecules. The initial signal is amplified by most signal transduction pathways. This means that a single ligand molecule can activate multiple molecules of a downstream target. Proteins that relay a signal are most commonly phosphorylated at one or more sites, activating or inactivating the protein. Kinases catalyze the...
01:22Diversity in Cell Signaling Responses
The physiological function of a cell and cellular communication are outcomes of a range of extrinsic signals, intracellular signaling pathways, and cellular responses. No two cell types express the same repertoire of signaling components. Receptors are highly selective for their cognate ligands, but once activated, they can alter multiple cellular processes such as DNA transcription, protein synthesis, and metabolic activity.
Graded and Abrupt Responses
Some signaling systems generate...
Graded and Abrupt Responses
Some signaling systems generate...