Related Experiment Video
Updated: May 19, 2026
06:45
Transmembrane Domain Oligomerization Propensity determined by ToxR Assay
Published on: May 26, 2011
Disruption of gingipain oligomerization into non-covalent cell-surface attached complexes
Maryta Sztukowska1, Florian Veillard, Barbara Potempa
1Oral Health and Systemic Diseases Research Group, University of Louisville School of Dentistry, Louisville, KY 40202, USA.
Biological Chemistry
|September 5, 2012
Summary
A conserved motif in Porphyromonas gingivalis gingipains is crucial for their assembly. Disrupting this motif caused Kgp activity to be secreted, confirming its role in posttranslational processing and complex formation.
Area of Science:
- Microbiology
- Molecular Biology
- Protein Biochemistry
Background:
- Porphyromonas gingivalis utilizes RgpA and Kgp gingipains, which are surface-displayed non-covalent complexes.
- These complexes consist of endoprotease catalytic and hemagglutinin-adhesin domains.
- A conserved motif within each domain has been hypothesized to mediate oligomerization.
Purpose of the Study:
- To investigate the role of the conserved motif in the posttranslational processing and assembly of Porphyromonas gingivalis Kgp.
- To determine if the conserved motif functions as an oligomerization motif.
Main Methods:
- Mutagenesis of conserved motif residues within the Kgp catalytic domain.
- Introduction of hexahistidine tags to disrupt the motif.
- Analysis of Kgp secretion and activity in the growth media.
Main Results:
- Modifications disrupting the conserved motif resulted in the secretion of the entire Kgp activity into the growth media.
- The secreted Kgp was predominantly in a form lacking a functional His-tag.
- These findings indicate the motif's essential role in proper protein processing and complex assembly.
Conclusions:
- The conserved motif within the Kgp catalytic domain is essential for the correct posttranslational processing and assembly of Porphyromonas gingivalis gingipains.
- Disruption of this motif leads to the secretion of Kgp activity, confirming its role in mediating the formation of functional, cell-surface-associated complexes.
Related Concept Videos
01:17Intracellular Signaling Affects Focal Adhesions
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...
01:39Mechanism of Filopodia Formation
Filopodia are thin, actin-rich cellular protrusions that play an important role in many fundamental cellular functions. They vary in their occurrence, length, and positioning in different cell types, suggesting their diverse roles.
Their main function is to guide migrating cells during normal tissue morphogenesis or cancer metastasis by recognizing and making initial contacts with the extracellular matrix. However, they can also act as stationary cell anchors or help to establish communication...
Their main function is to guide migrating cells during normal tissue morphogenesis or cancer metastasis by recognizing and making initial contacts with the extracellular matrix. However, they can also act as stationary cell anchors or help to establish communication...
01:35Disassembly of Intermediate Filaments
Intermediate filaments (IFs) do not undergo spontaneous disassembly. Enzymes, kinases, and phosphatases add and remove phosphates from specific sites to regulate their disassembly. The IF concentration in the cytoplasm also regulates the disassembly. If the concentration crosses a threshold, it activates the protein kinases in the vicinity, allowing the phosphorylation of IFs.
Keratin proteins, found at the cell periphery near cell junctions, undergo a cycle of assembly and disassembly. In Type...
Keratin proteins, found at the cell periphery near cell junctions, undergo a cycle of assembly and disassembly. In Type...
01:19Actin Filament Depolymerization
Actin filaments (F-actin) are composed of actin subunits. The dissociation of actin monomers can occur from either end of F-actin. The rate of dissociation is faster from the minus-end or the pointed end, where the actin subunits exist with a bound ADP, together known as ADP-actin. The depolymerization of F-actin is aided by proteins, including the actin-depolymerizing factor (ADF) and cofilin family of proteins, gelsolin, and glia maturation factor (GMF).
In F-actin, the ADF/cofilin proteins...
In F-actin, the ADF/cofilin proteins...
01:12GPCR Desensitization
G protein-coupled receptor (GPCR) signaling plays a crucial role in cell functioning. GPCR desensitization is an equally essential process. It allows cells to respond to changing environments and regain sensitivity to new stimuli while preventing unnecessary stimulation when no longer needed. Prolonged exposure to stimuli leads to GPCR desensitization. It involves blocking the receptors from binding and activating additional G proteins. This inhibits activation of downstream effectors, thereby...
01:16Cell Motility through Blebbing
Blebs are a type of membrane protrusion formed by the internal hydrostatic pressure of the cytoplasm. Blebs are observed in several cell types, including fibroblasts, immune cells, and single-celled organisms like the amoeba. The primary function of blebs is cell locomotion and apoptosis, but they are also found during necrosis and cell division. The life cycle of a bleb comprises an initiation phase followed by the expansion and retraction phases.
Blebbing Through the Matrix
In multicellular...
Blebbing Through the Matrix
In multicellular...