Search research articles

ABOUT JoVE

Overview Leadership Blog JoVE Help Center

AUTHORS

Publishing Process Editorial Board Scope & Policies Peer Review FAQ Submit

LIBRARIANS

Testimonials Subscriptions Access Resources Library Advisory Board FAQ

RESEARCH

JoVE Journal Methods Collections JoVE Encyclopedia of Experiments Archive

EDUCATION

JoVE Core JoVE Business JoVE Science Education JoVE Lab Manual Faculty Resource Center Faculty Site

Terms & Conditions of Use

Related Concept Videos

Mechanical Systems

Mechanical Systems

Mechanical systems are analogous to to electrical networks where springs and masses play similar roles to inductors and capacitors, respectively. A viscous damper in mechanical systems functions similarly to a resistor in electrical networks, dissipating energy. The forces acting on a mass in such systems include an applied force in the direction of motion, counteracted by forces from the spring, a viscous damper, and the mass's acceleration. This interplay of forces is mathematically...

Electro-mechanical Systems

Electro-mechanical Systems

Electromechanical systems are intricate configurations that effectively combine electrical and mechanical elements to achieve a desired outcome. Central to many of these systems is the DC motor, a device that converts electrical energy into mechanical motion, enabling various applications ranging from simple fans to complex robotic mechanisms.
A key component of the DC motor is the armature, a rotating circuit positioned within a magnetic field. As an electric current passes through the...

Exocrine Glands: Types of Secretions

Exocrine Glands: Types of Secretions

Exocrine glands produce and release a variety of glandular products. Exocrine glands can be classified into serous, mucous, or mixed types based on their secretory products.
Serous glands produce watery secretions rich in digestive enzymes and proteins. The constituent cells of the serous gland have centrally located nuclei and eosinophilic secretory granules in the cytoplasm. The parotid gland is an example of a serous gland. It secretes saliva, which contains enzymes, such as lipases and...

Gram-negative Bacterial Protein Secretion Systems

Gram-negative Bacterial Protein Secretion Systems

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):...

Second Order systems II

Second Order systems II

In an underdamped second-order system, where the damping ratio ζ is between 0 and 1, a unit-step input results in a transfer function that, when transformed using the inverse Laplace method, reveals the output response. The output exhibits a damped sinusoidal oscillation, and the difference between the input and output is termed the error signal. This error signal also demonstrates damped oscillatory behavior. Eventually, as the system reaches a steady state, the error diminishes to zero.

Reaction Mechanisms

Reaction Mechanisms

Chemical reactions often occur in a stepwise fashion, involving two or more distinct reactions taking place in a sequence. A balanced equation indicates the reacting species and the product species, but it reveals no details about how the reaction occurs at the molecular level. The reaction mechanism (or reaction path) provides details regarding the precise, step-by-step process by which a reaction occurs.
For instance, the decomposition of ozone appears to follow a mechanism with two steps:

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by

Same author

Graphene Nanosensor for the Detection of Small Organic Compounds Using an Insect Olfactory Receptor.

Advanced materials (Deerfield Beach, Fla.)·2026

Same author

An Integrative Biophysical and Computational Workflow Uncovers New Allosteric Sites and Modulators of the Human A<sub>2A</sub> Adenosine Receptor.

ACS chemical biology·2026

Same author

G521 is the gatekeeper and a key transmembrane domain contact residue of <i>Candida albicans</i> Cdr1.

mBio·2026

Same author

Acylation of the RTX toxin MbxA stimulates host membrane disruption through a specific interaction with cholesterol.

Biochimica et biophysica acta. Biomembranes·2025

Same author

Molecular Insights into CLD Domain Dynamics and Toxin Recruitment of the HlyA E. coli T1SS.

Journal of molecular biology·2025

Same author

Structural insights into the substrate binding mechanism of the class I dehydratase MadB.

Communications biology·2025

Search research articles

Related Experiment Video

Updated: Jan 28, 2026

Mechanisms Underlying Gut Hormone Secretion Using the Isolated Perfused Rat Small Intestine

Mechanisms Underlying Gut Hormone Secretion Using the Isolated Perfused Rat Small Intestine

Published on: February 26, 2019

Type I Secretion Systems-One Mechanism for All?

Olivia Spitz¹, Isabelle N Erenburg¹, Tobias Beer¹

¹Institute of Biochemistry, Heinrich Heine University Düsseldorf, Düsseldorf, Germany.

Microbiology Spectrum

|March 9, 2019

Summary

Type I secretion systems (T1SS) in Gram-negative bacteria secrete large proteins across membranes. Recent findings reveal variations in this secretion process, challenging the classic model.

More Related Videos

Quantifying Yersinia pseudotuberculosis Type III Secretion System Activity Following Iron Starvation and Anaerobic Growth

Quantifying Yersinia pseudotuberculosis Type III Secretion System Activity Following Iron Starvation and Anaerobic Growth

Published on: May 31, 2024

High Resolution Electron Microscopy of the Helicobacter pylori Cag Type IV Secretion System Pili Produced in Varying Conditions of Iron Availability

High Resolution Electron Microscopy of the Helicobacter pylori Cag Type IV Secretion System Pili Produced in Varying Conditions of Iron Availability

Published on: November 21, 2014

Related Experiment Videos

Last Updated: Jan 28, 2026

Mechanisms Underlying Gut Hormone Secretion Using the Isolated Perfused Rat Small Intestine

Mechanisms Underlying Gut Hormone Secretion Using the Isolated Perfused Rat Small Intestine

Published on: February 26, 2019

Quantifying Yersinia pseudotuberculosis Type III Secretion System Activity Following Iron Starvation and Anaerobic Growth

Quantifying Yersinia pseudotuberculosis Type III Secretion System Activity Following Iron Starvation and Anaerobic Growth

Published on: May 31, 2024

High Resolution Electron Microscopy of the Helicobacter pylori Cag Type IV Secretion System Pili Produced in Varying Conditions of Iron Availability

High Resolution Electron Microscopy of the Helicobacter pylori Cag Type IV Secretion System Pili Produced in Varying Conditions of Iron Availability

Published on: November 21, 2014

Area of Science:

Microbiology
Molecular Biology
Bacterial Pathogenesis

Background:

Type I secretion systems (T1SS) are crucial for Gram-negative bacteria, particularly pathogens.
They transport diverse proteins like toxins and enzymes across the cell envelope.
Substrates typically feature a C-terminal secretion signal and GG repeats.

Purpose of the Study:

To review current knowledge on T1SS substrate secretion mechanisms.
To highlight recent discoveries modifying the traditional understanding of T1SS function.
To discuss the diversity and evolution of T1SS.

Main Methods:

Literature review and synthesis of existing research on T1SS.
Analysis of substrate characteristics and secretion pathway components.
Comparison of established T1SS models with emerging data.

Main Results:

T1SS secrete unfolded substrates up to 1,500 kDa in a single step.
GG repeats bind extracellular Ca2+ to trigger substrate folding.
Emerging evidence shows T1SS can operate with periplasmic intermediates, deviating from the classic model.

Conclusions:

T1SS represent a versatile secretion mechanism in Gram-negative bacteria.
The canonical T1SS pathway is not universally conserved, with notable modifications.
Further research is needed to fully elucidate the spectrum of T1SS functions and mechanisms.