Related Experiment Video

Updated: Sep 6, 2025

An Electroporation Method to Transform Rickettsia spp. with a Fluorescent Protein-Expressing Shuttle Vector in Tick Cell Lines
07:18

An Electroporation Method to Transform Rickettsia spp. with a Fluorescent Protein-Expressing Shuttle Vector in Tick Cell Lines

Published on: October 11, 2022

1.9K

A patatin-like phospholipase mediates Rickettsia parkeri escape from host membranes

Gina M Borgo1,2, Thomas P Burke2,3, Cuong J Tran1,2

  • 1Division of Infectious Disease and Vaccinology, School of Public Health, University of California, Berkeley, Berkeley, CA, USA.

Nature Communications
|June 27, 2022
PubMed

Insights

Rickettsia parkeri uses a patatin-like phospholipase A2 enzyme (Pat1) to escape host cells and spread. This enzyme is crucial for bacterial survival, promoting cytosol invasion and avoiding immune responses.

Area of Science:

  • Microbiology
  • Cell Biology
  • Infectious Diseases

Background:

  • Rickettsia species are intracellular bacteria causing spotted fever group diseases.
  • These pathogens invade host cells, replicate in the cytosol, and spread intercellularly.
  • Bacterial escape from host membranes is vital for cytosolic access and immune evasion.

Purpose of the Study:

  • To investigate the role of a patatin-like phospholipase A2 enzyme (Pat1) in Rickettsia parkeri infection.
  • To determine Pat1's function in host cell invasion, intracellular survival, and cell-to-cell spread.

Main Methods:

  • Infection studies in a mouse model.
  • Cellular assays examining vacuole escape and host immune interactions.
  • Analysis of bacterial actin-based motility.

Main Results:

  • Pat1 is essential for Rickettsia parkeri infection in vivo.
  • Pat1 facilitates escape from single and double membrane-bound vacuoles into the host cytosol.
  • Pat1 aids in avoiding host galectins and polyubiquitin, preventing p62 recruitment, and promoting actin motility and cell-cell spread.

Conclusions:

  • Patatin-like phospholipase A2 (Pat1) is a key virulence factor for Rickettsia parkeri.
  • Pat1 mediates bacterial escape from host membranes and promotes efficient cell-to-cell spread.
  • Targeting Pat1 may offer a strategy to combat Rickettsia infections.

More Related Videos

Monitoring Activation of the Antiviral Pattern Recognition Receptors RIG-I And PKR By Limited Protease Digestion and Native PAGE12:43

Monitoring Activation of the Antiviral Pattern Recognition Receptors RIG-I And PKR By Limited Protease Digestion and Native PAGE

Published on: July 29, 2014

12.4K
Identification of Inositol Phosphate or Phosphoinositide Interacting Proteins by Affinity Chromatography Coupled to Western Blot or Mass Spectrometry08:07

Identification of Inositol Phosphate or Phosphoinositide Interacting Proteins by Affinity Chromatography Coupled to Western Blot or Mass Spectrometry

Published on: July 26, 2019

8.6K

Related Concept Videos

Intracellular Movement of Viruses and Bacteria01:10

Intracellular Movement of Viruses and Bacteria

Intracellular bacteria and viruses often comprise a group of highly infectious pathogens that can cause several diseases. Bacterial pathogens include those belonging to the genus Rickettsia responsible for conditions such as rocky mountain spotted fever and the Mediterranean spotted fever; Chlamydia, a genus responsible for a sexually transmitted disease; Coxiella burnetii, an agent responsible for Q fever. Viral pathogens include vaccinia—a poxvirus, and herpes simplex virus—a...
2.9K
Phosphoinositides and PIPs01:42

Phosphoinositides and PIPs

Phosphoinositides are a group of phospholipids containing a glycerol backbone with two fatty acid chains and a phosphate attached to a myoinositol sugar ring. The inositol head group extends into the cytoplasm, where it is modified by adding phosphate groups to form phosphatidylinositol phosphates or PIPs.
Different phosphoinositides are synthesized and recruited on the cytosolic face of the plasma membrane. The localization of specific phosphoinositides concentrated in separate membrane...
8.7K
IP3/DAG Signaling Pathway01:11

IP3/DAG Signaling Pathway

Membrane lipids such as phosphatidylinositol (PI) are precursors for several membrane-bound and soluble second messengers. Specific kinases phosphorylate PI and produce phosphorylated inositol phospholipids. One such inositol phospholipids are the  phosphatidylinositol-4,5 bisphosphate [PI(4,5)P2], present in the inner half of the lipid bilayer. Upon ligand binding, GPCR stimulates Gq proteins to turn on phospholipase Cꞵ. Activated phospholipase Cꞵ cleaves PI(4,5)P2 and...
12.4K
Mechanism of Lamellipodia Formation01:31

Mechanism of Lamellipodia Formation

Cells migrating in response to external stimuli form lamellipodia, which are thin membrane protrusions supported by a mesh of linked, branched, or unbranched actin filaments. These actin filaments interact with myosin motor proteins, creating the dynamic actomyosin complex within the cytoskeleton. Contractility, or the ability to generate contractile stress, is inherent to the actomyosin complex. It helps cells detect the stiffness of the surrounding ECM and exert contractile force for...
2.7K
The JAK-STAT Signaling Pathway01:20

The JAK-STAT Signaling Pathway

Several cytokine receptors have tightly bound Janus kinase or JAK proteins attached at their cytosolic tail. Small signaling molecules such as cytokines, growth hormones, or prolactins bind to the cytokine receptors and initiate their dimerization. The dimerization brings the cytosolic JAKs together that trans-phosphorylate and activates each other. The activated JAKs now phosphorylate cytosolic tails of the cytokine receptors, which serve as binding sites for adaptor proteins such as  SH2...
9.2K
Formation of Lipopolysaccharides01:19

Formation of Lipopolysaccharides

Lipopolysaccharides (LPS) are crucial components of the outer membrane of Gram-negative bacteria, serving both structural and functional roles. It contributes to membrane stability and protects bacteria from host immune responses. LPS is composed of three major regions—lipid A, a core oligosaccharide, and an O antigen. The biosynthesis and assembly of LPS involve a highly coordinated set of enzymatic reactions and transport mechanisms. Additionally, LPS is recognized as an endotoxin,...
93