The Helicobacter pylori Cag Type IV Secretion System.
Timothy L Cover1, D Borden Lacy2, Melanie D Ohi3
1Department of Medicine, Vanderbilt University School of Medicine, Nashville, TN, USA; Department of Pathology, Microbiology, and Immunology, Vanderbilt University School of Medicine, Nashville, TN, USA; Veterans Affairs Tennessee Valley Healthcare System, Nashville, TN, USA.
Trends in Microbiology
|May 27, 2020
Summary
Helicobacter pylori's cag pathogenicity island, including its Cag type IV secretion system (Cag T4SS), is linked to gastric cancer. This review explores the Cag T4SS structure, function, and role in disease development.
Area of Science:
- Microbiology
- Molecular Biology
- Oncology
Background:
- * Helicobacter pylori colonization is a significant risk factor for gastric cancer.
- * The cag pathogenicity island (cag PAI) encodes essential virulence factors, including CagA and the Cag type IV secretion system (Cag T4SS).
- * The Cag T4SS is crucial for translocating effector proteins into host cells, contributing to pathogenesis.
Purpose of the Study:
- * To review recent advancements in understanding the molecular architecture of the H. pylori Cag T4SS.
- * To elucidate the structure and function of the Cag T4SS.
- * To discuss the role of the Cag T4SS in the development of gastric cancer.
Main Methods:
- * Literature review of recent scientific discoveries.
- * Analysis of structural and functional data related to the Cag T4SS.
- * Examination of studies linking Cag T4SS activity to gastric cancer pathogenesis.
Main Results:
- * The H. pylori Cag T4SS exhibits a complex molecular structure, distinct from other bacterial type IV secretion systems.
- * Recent findings highlight key components and their assembly within the Cag T4SS.
- * The Cag T4SS actively contributes to host cell manipulation, promoting gastric carcinogenesis.
Conclusions:
- * The intricate structure of the Cag T4SS is central to its function in H. pylori pathogenesis.
- * Further research into the Cag T4SS offers insights into gastric cancer mechanisms.
- * Understanding the Cag T4SS is vital for developing targeted therapeutic strategies against H. pylori-associated gastric cancer.
Related Concept Videos
01:17Gram-negative Bacterial Protein Secretion Systems
549
Gram-negative bacteria utilize sophisticated protein secretion systems to transport proteins across their double-membrane envelope into the extracellular environment or host cells. Based on their mechanism of action, these systems are classified into one-step and two-step pathways.One-Step Secretion Systems (Types I, III, IV, and VI)One-step secretion systems bypass the periplasm entirely, forming a continuous channel that spans both the inner and outer membranes:Type I Secretion System (T1SS):...
549
01:26Bacterial Translocation and Protein Secretion
363
Bacterial protein secretion involves translocation systems to ensure proteins reach their designated locations, including the plasma membrane, periplasm, outer membrane, or the external environment. These translocation systems are vital for bacterial physiology, supporting processes like membrane assembly, enzymatic activity in the periplasm, and interactions with the external environment. The division of labor between Sec and Tat pathways ensures efficiency in handling proteins with diverse...
363
01:22Pathophysiology of Peptic Ulcer Disease: Injurious Factors
971
Peptic ulcers are sores on the stomach's inner lining and the upper small intestine, which are the result of disruptions in the mucosal layer that houses parietal cells which produce gastric acid, and chief cells which secrete pepsinogen.
In the antrum region, G cells secrete the gastrin hormone that binds to gastrin-cholecystokinin-B (CCK2) receptors on parietal and enterochromaffin-like (ECL) cells in the fundic glands. Simultaneously, the vagus nerve releases acetylcholine, which binds...
In the antrum region, G cells secrete the gastrin hormone that binds to gastrin-cholecystokinin-B (CCK2) receptors on parietal and enterochromaffin-like (ECL) cells in the fundic glands. Simultaneously, the vagus nerve releases acetylcholine, which binds...
971
01:19Mechanism of Conjugation
606
Bacterial conjugation is a mechanism of horizontal gene transfer that enables the exchange of genetic material between bacterial cells through direct contact. This process is facilitated by a donor cell carrying a conjugative plasmid, which encodes genes necessary for pilus formation, DNA replication, and transfer. The conjugative plasmid plays a central role in initiating and executing the transfer of genetic material.The tra region of the conjugative plasmid encodes proteins responsible for...
606
01:16Treating Helicobacter pylori in Peptic Ulcers: Antimicrobial Therapy
909
Helicobacter pylori, a resilient gram-negative bacterium, can thrive in the stomach's harsh, acidic environment. Infection with H. pylori leads to a cascade of events within the stomach lining. One of the critical disruptions caused by this bacterium is the interference with somatostatin production, a hormone responsible for regulating acid secretion. This interference tips the balance, escalating acid secretion and diminishing bicarbonate levels. This imbalance compromises the defensive...
909
01:25Mucosal Barrier of the Stomach
1.9K
The gastric glands contain parietal cells that secrete hydrochloric acid (HCl) for digestion. The cells secrete HCl because it is highly corrosive and essential for breaking down food. To achieve this, they secrete hydrogen and chloride ions into the lumen of the gastric glands, which combine to form HCl.
Within parietal cells, carbonic acid is first formed through the reaction of water and carbon dioxide. The dissociation of carbonic acid releases bicarbonate and hydrogen ions. The bicarbonate...
Within parietal cells, carbonic acid is first formed through the reaction of water and carbon dioxide. The dissociation of carbonic acid releases bicarbonate and hydrogen ions. The bicarbonate...
1.9K