Related Experiment Video
Updated: May 16, 2026
06:44
Bioluminescence Resonance Energy Transfer (BRET)-Based Assay for Measuring Interactions of CRAF with 14-3-3 Proteins in Live Cells
Published on: March 1, 2024
The capping domain in RalF regulates effector functions
Eric Alix1, Laurent Chesnel, Brad J Bowzard
1Department of Microbial Pathogenesis, Yale University School of Medicine, Boyer Center for Molecular Medicine, New Haven, Connecticut, United States of America. eric.alix@yale.edu
Plos Pathogens
|November 21, 2012
Summary
The Legionella RalF protein
Area of Science:
- Microbiology
- Molecular Biology
- Cell Biology
Background:
- Legionella pneumophila effector protein RalF activates host ADP-ribosylation factor (Arf) via its Sec7 domain.
- RalF's C-terminal region, termed a capping domain, interacts with the Sec7 domain, potentially regulating its activity.
Purpose of the Study:
- Investigate the role of the RalF capping domain by comparing Legionella RalF (LpRalF) and Rickettsia prowazekii RalF (RpRalF).
- Determine how the capping domain influences GEF activity, host cell localization, and effector functions.
Main Methods:
- Biochemical assays to assess guanine nucleotide exchange factor (GEF) activity.
- Comparative analysis of LpRalF and RpRalF effector functions and cellular localization.
Main Results:
- Both LpRalF and RpRalF possess functional Sec7 domains and capping domains that regulate GEF activity.
- The capping domain dictates RalF's intracellular localization and distinct effector functions.
- LpRalF's capping domain modulates secretory pathway membrane transport, while RpRalF's modulates actin dynamics.
Conclusions:
- The C-terminal capping domain is crucial for regulating RalF's GEF activity and determining its specific functions within host cells.
- Divergence in capping domain function leads to distinct in vivo roles for RalF proteins from different bacterial species.
More Related Videos
Related Concept Videos
01:14Rab Proteins
Rab proteins constitute the largest family of monomeric GTPases, of which 70 members are present in humans. Rab proteins and their effectors regulate consecutive stages of vesicle transport such as vesicle transport, docking, and fusion to the correct recipient membrane.
Rab proteins switch between a cytosolic, GDP-bound inactive state and a membrane-anchored, GTP-bound active state. By themselves, Rabs show slow rates of GDP/GTP exchange and GTP hydrolysis. Thus, Rab proteins are considered...
Rab proteins switch between a cytosolic, GDP-bound inactive state and a membrane-anchored, GTP-bound active state. By themselves, Rabs show slow rates of GDP/GTP exchange and GTP hydrolysis. Thus, Rab proteins are considered...
01:23Transcriptional Regulation: Riboswitches
Riboswitches are RNA elements that regulate gene expression by altering their secondary structures in response to specific effector molecules. These elements, located in the leader regions of certain mRNAs, act as transcriptional regulators by toggling between alternative conformations to control downstream gene expression. Riboswitch-mediated regulation is a precise mechanism for modulating biosynthetic pathways, as exemplified by the riboflavin biosynthesis pathway in Bacillus...
01:16Calmodulin-dependent Signaling
Calmodulin (CaM) is a calcium-binding protein in eukaryotes that controls various calcium-regulated cellular processes. It has four calcium-binding sites that bind calcium to form the calcium-calmodulin ( Ca2+-CaM) complex. GPCR stimulation increases the calcium levels in the cells that bind to CaM and induces a conformational change.
The Ca2+-CaM complex does not have enzymatic activity by itself. Instead, the complex binds downstream target proteins, including membrane proteins or enzymes,...
The Ca2+-CaM complex does not have enzymatic activity by itself. Instead, the complex binds downstream target proteins, including membrane proteins or enzymes,...
01:25Rab Cascades
Rab GTPases act in a regulated cascade during membrane fusion, helping the lipid bilayers mix. The Rab family of proteins are active when bound to GTP, and inactive when bound to GDP. Hence, they act as guanine nucleotide-dependent molecular switches. Rab-GTP recognizes and binds to long or short-range tethering proteins to capture the target vesicle. These tethers coordinate with SNAREs on the vesicle and the target membrane to assemble the trans SNARE complex that locks the mixing bilayers.
01:30Assembly of Signaling Complexes
Multiprotein signaling complexes are formed in a dynamic process involving protein-protein interactions at the cytoplasmic domain of transmembrane receptors or enzymatic and non-enzymatic proteins associated with the receptor. These complexes ensure the activation and propagation of intracellular signals that regulate cell functions.
Interaction domains in cell signaling
Interaction domains recognize exposed features of their binding partners containing post-translationally modified sequences,...
Interaction domains in cell signaling
Interaction domains recognize exposed features of their binding partners containing post-translationally modified sequences,...
01:28Global Regulatory Systems
Global regulatory systems in bacteria enable rapid and coordinated responses to environmental changes by integrating sensory inputs with gene expression, ensuring efficient adaptation to fluctuating conditions. Key global regulatory mechanisms include regulons, two-component systems, sigma factors, and secondary messengers.Regulons and Global RegulatorsA regulon is a collection of genes and operons controlled by a common global regulator. These regulators enable bacteria to prioritize resource...