Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Experiment Videos

Allostery and proteolysis: two novel modes of regulating integrin function

J W Smith1

  • 1Cancer Research Center, Burnham Institute, La Jolla, California, USA.

Matrix Biology : Journal of the International Society for Matrix Biology
|December 24, 1997
PubMed
Summary

This article explores two new ways that integrins, proteins that help cells communicate with their surroundings, might be controlled. Researchers propose that these proteins can be cut by enzymes or regulated by metal ions to change how they bind to other molecules.

Related Concept Videos

You might also read

Related Articles

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

Sort by
Same author

Resection of hepatic and pulmonary metastases from colorectal cancer.

Surgical oncology·1992
Same author

An enzyme-linked immunosorbent assay for enumeration of Pneumocystis carinii in vitro and in vivo.

Journal of clinical microbiology·1992
Same author

Production of serum amyloid A and C-reactive protein by HepG2 cells stimulated with combinations of cytokines or monocyte conditioned media: the effects of prednisolone.

Clinical and experimental immunology·1992
Same author

The beta-tubulin gene from rat and human isolates of Pneumocystis carinii.

Molecular microbiology·1992
Same author

Delayed postoperative bleeding from polytetrafluoroethylene carotid artery patches.

Journal of vascular surgery·1992
Same author

Inhibition of colonic motility by cholecystokinin.

Annals of medicine·1992

Area of Science:

  • Cellular signaling pathways within molecular biology
  • Integrin allostery mechanisms in structural biochemistry

Background:

Cellular communication relies on complex protein networks that bridge the gap between internal and external environments. Integrins serve as primary mediators for this bidirectional information exchange across the plasma membrane. Despite their importance, the precise mechanisms governing their activation states remain incompletely understood. Prior research has shown that these receptors undergo significant conformational changes during signal transduction. That uncertainty drove interest in identifying novel regulatory pathways beyond canonical models. No prior work had resolved how specific enzymatic or chemical modifications might dictate binding affinity. This gap motivated a closer look at potential proteolytic and ionic control points. The current discussion synthesizes existing reports to propose testable models for these regulatory processes.

Purpose Of The Study:

The aim of this study is to propose two novel regulatory modes for integrin function. Researchers seek to address how these receptors manage bidirectional information flow between the cytoplasm and the extracellular matrix. The motivation stems from the need to identify specific mechanisms that dictate receptor binding affinity. This work explores the possibility that enzymatic cleavage of the cytoplasmic domain acts as a regulatory switch. It also examines how divalent ion binding sites might influence the ligand binding pocket through allosteric effects. The study addresses the gap in current knowledge regarding the chemical and structural control of these proteins. By synthesizing existing reports, the authors provide a clear set of hypotheses for future experimental verification. This effort clarifies the potential for diverse regulatory strategies in maintaining cellular homeostasis.

Keywords:
cell signalingextracellular matrixprotein regulationreceptor affinity

Frequently Asked Questions

The researchers propose that cleavage of the cytoplasmic tail alters ligand binding affinity, while divalent ions regulate the binding site through allosteric control of association and dissociation rates.

The authors identify divalent ion binding sites as the specific components responsible for the allosteric regulation of the ligand binding site.

Experimental testing is necessary to confirm these hypotheses because current evidence relies on literature reports rather than direct, controlled observation of these specific regulatory events.

The cytoplasmic tail acts as a proteolytic substrate, meaning it is a target for enzymatic cleavage that potentially changes the functional state of the receptor.

Related Experiment Videos

Main Methods:

The review approach involves a systematic synthesis of existing scientific literature regarding receptor modulation. Researchers evaluated reported evidence to formulate testable hypotheses about protein regulation. This methodology focuses on identifying potential enzymatic and chemical pathways that influence receptor behavior. The analysis integrates findings from diverse studies to construct a coherent model of signaling control. Investigators utilized conceptual mapping to link known protein domains with proposed regulatory functions. This approach prioritizes the identification of mechanisms that remain unverified by direct experimentation. The study design centers on theoretical refinement rather than empirical data generation. This synthesis provides a foundation for future laboratory investigations into these specific regulatory phenomena.

Main Results:

Key findings from the literature suggest that the cytoplasmic domain of the receptor functions as a substrate for proteolytic enzymes. This cleavage event is proposed to directly impact the affinity of the receptor for its extracellular ligands. Additionally, the analysis indicates that divalent ion binding sites operate as independent regulators of the ligand binding pocket. These sites exert control over the speed of both ligand association and dissociation. The evidence implies that these two modes of regulation are distinct from previously established signaling pathways. Reports highlight that these processes could be fundamental to the bidirectional transmission of information across the membrane. The synthesis demonstrates that these hypotheses are grounded in existing observations of protein behavior. These results provide a framework for understanding how structural modifications might dictate receptor activity.

Conclusions:

The authors propose that cytoplasmic tail cleavage serves as a mechanism to modulate receptor binding affinity. This model suggests that enzymatic processing of the intracellular domain alters the functional state of the protein. Furthermore, the researchers hypothesize that divalent ions influence binding sites through distinct allosteric pathways. These ions appear to independently govern the kinetics of ligand association and dissociation. The synthesis implies that these two modes of regulation could operate in tandem or separately within cellular contexts. Experimental validation remains necessary to confirm these theoretical frameworks in living systems. Future studies might determine the specific proteases or ion concentrations involved in these regulatory events. These proposed mechanisms offer a new perspective on the dynamic control of cell-matrix interactions.

The phenomenon involves the independent control of ligand association and dissociation rates by separate ion binding sites, which contrasts with models where these processes are coupled.

The authors imply that these regulatory modes provide a way for cells to fine-tune their interactions with the extracellular matrix in response to environmental signals.