Related Experiment Video
Updated: Aug 12, 2025
08:56
Imaging Ca2+ Responses During Shigella Infection of Epithelial Cells
Published on: May 24, 2018
5.6K
Ca2+-calmodulin signalling at the host-pathogen interface
Joseph J Wanford1, Charlotte Odendall1
1School of Immunology and Microbial Sciences, Kings College London, London, UK.
Current Opinion in Microbiology
|January 30, 2023
Summary
Calcium ions (Ca2+) regulate innate immunity and host-bacteria interactions. Bacterial virulence factors can alter Ca2+ signals during infection, impacting host defenses and pathogen survival.
Area of Science:
- Cellular Biology
- Immunology
- Microbiology
Background:
- Calcium ions (Ca2+) are vital for numerous eukaryotic cellular processes.
- Ca2+ signaling plays a critical role in innate immunity, particularly at the host-bacteria interface.
- Pathogen virulence factors can manipulate Ca2+ signaling during infection, leading to complex outcomes.
Purpose of the Study:
- To review the role of Ca2+ in antibacterial innate immunity.
- To discuss host factors that regulate Ca2+-dependent immune responses.
- To examine bacterial effectors that target Ca2+-calmodulin signaling during infection.
Main Methods:
- Literature review of recent studies on Ca2+ signaling and immunity.
- Analysis of host-pathogen interactions involving Ca2+.
- Examination of bacterial virulence strategies targeting Ca2+ pathways.
Main Results:
- Ca2+ signals are initiated upon microbial exposure, influencing host cell physiology.
- Atypical Ca2+ signaling occurs during infections with host-adapted pathogens due to virulence factors.
- Bacterial effectors can modulate Ca2+ homeostasis to facilitate infection.
Conclusions:
- Ca2+ is a key regulator of antibacterial immunity.
- Understanding Ca2+-dependent host factors and bacterial manipulation strategies is crucial for combating infections.
Related Concept Videos
01:16Calmodulin-dependent Signaling
5.2K
Calmodulin (CaM) is a calcium-binding protein in eukaryotes that controls various calcium-regulated cellular processes. It has four calcium-binding sites that bind calcium to form the calcium-calmodulin ( Ca2+-CaM) complex. GPCR stimulation increases the calcium levels in the cells that bind to CaM and induces a conformational change.
The Ca2+-CaM complex does not have enzymatic activity by itself. Instead, the complex binds downstream target proteins, including membrane proteins or enzymes,...
The Ca2+-CaM complex does not have enzymatic activity by itself. Instead, the complex binds downstream target proteins, including membrane proteins or enzymes,...
5.2K
01:25cAMP-dependent Protein Kinase Pathways
6.5K
Cyclic Adenosine Monophosphate (cAMP) is an essential second messenger that activates protein kinase A (PKA) and regulates various biological processes. A single epinephrine molecule binds to GPCR and activates several heterotrimeric G proteins, each stimulating multiple adenylyl cyclase, amplifying the signal, and synthesizing large numbers of cAMP molecules. Small changes in cAMP concentration affect PKA activity. The binding of four cAMP molecules induces a conformational change in PKA,...
6.5K
01:17Intracellular Signaling Affects Focal Adhesions
2.7K
Integrins act both as extracellular input receivers and as intracellular processing activators. As their name suggests, integrins are entirely integrated into the membrane structure. Their hydrophobic membrane-spanning regions interact with the phospholipid bilayer's hydrophobic region. These membrane receptors provide extracellular attachment sites for effectors like hormones and growth factors. They activate intracellular response cascades when their effectors are bound and active.
Some...
Some...
2.7K
01:24Intracellular Signaling Cascades
47.2K
Once a ligand binds to a receptor, the signal is transmitted through the membrane and into the cytoplasm. The continuation of a signal in this manner is called signal transduction. Signal transduction only occurs with cell-surface receptors, which cannot interact with most components of the cell, such as DNA. Only internal receptors can interact directly with DNA in the nucleus to initiate protein synthesis. When a ligand binds to its receptor, conformational changes occur that affect the...
47.2K
01:09GPCRs Regulate Adenylyl Cylase Activity
5.8K
Some GPCRs transmit signals through adenylyl cyclase (AC), a transmembrane enzyme. AC helps synthesize second messenger cyclic adenosine monophosphate (cAMP). AC catalyzes cyclization reaction and converts ATP to cAMP by releasing a pyrophosphate. The pyrophosphate is further hydrolyzed to phosphate by the enzyme pyrophosphatase, which drives cAMP synthesis to completion. However, cAMP is rapidly degraded to 5′ AMP by the enzymes phosphodiesterase (PDE), preventing overstimulation of...
5.8K
01:15Amplifying Signals via Second Messengers
7.1K
Many receptor binding ligands are hydrophilic; they do not cross the cell membrane but bind to cell-surface receptors. Thus, their message must be relayed by second messengers present in the cell cytoplasm. There are several second messenger pathways, each with its own way of relaying information. For example, the G protein-coupled receptors can activate both phosphoinositol and cyclic AMP (cAMP) second messenger pathways. The phosphoinositol pathway is active when the receptor induces...
7.1K