Related Experiment Video
Updated: Mar 6, 2026
07:51
Pull-down of Calmodulin-binding Proteins
Published on: January 23, 2012
26.0K
The adaptors Grb10 and Grb14 are calmodulin-binding proteins
Irene García-Palmero1, Noemí Pompas-Veganzones1, Eduardo Villalobo2
1Department of Cancer Biology, Instituto de Investigaciones Biomédicas, Consejo Superior de Investigaciones Científicas and Universidad Autónoma de Madrid, Spain.
FEBS Letters
|March 16, 2017
Summary
Researchers found that Grb10 and Grb14 are calcium-dependent calmodulin-binding proteins, similar to Grb7. Binding affinity and calcium ion requirements were characterized, revealing distinct binding site characteristics across the Grb7 family.
Area of Science:
- Molecular Biology
- Protein-Protein Interactions
- Biochemistry
Background:
- The Grb7 family of adaptor proteins plays roles in cellular signaling.
- Calmodulin (CaM) is a crucial calcium-sensing protein involved in numerous cellular processes.
- Previous studies identified Grb7 as a Ca2+-dependent CaM-binding protein.
Purpose of the Study:
- To investigate whether other Grb7 family members, Grb10 and Grb14, also bind CaM in a Ca2+-dependent manner.
- To identify and characterize the CaM-binding sites within Grb10 and Grb14.
- To compare the CaM-binding properties of Grb7, Grb10, and Grb14.
Main Methods:
- Ca2+-dependent CaM-affinity chromatography was employed to identify CaM-binding proteins.
- Fluorescently labeled peptides corresponding to potential CaM-binding sites were synthesized and tested.
- Apparent affinity constants and minimal calcium ion requirements for CaM binding were determined.
- Deletion mutants of Grb7, Grb10, and Grb14 lacking identified binding sites were created and analyzed.
Main Results:
- Grb10 and Grb14 were identified as Ca2+-dependent CaM-binding proteins.
- The CaM-binding capacities of deletion mutants showed a hierarchy of binding loss: Grb7 >> Grb14 > Grb10.
- Grb7 appears to have a single CaM-binding site, while Grb10 and Grb14 possess multiple or accessory binding sites.
Conclusions:
- Grb10 and Grb14, like Grb7, are Ca2+-dependent calmodulin-binding proteins.
- The Grb7 protein family exhibits varying numbers and characteristics of CaM-binding sites.
- These findings contribute to understanding the regulation of Grb7 family proteins by Ca2+ and calmodulin.
Related Concept Videos
01:16Calmodulin-dependent Signaling
6.8K
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,...
6.8K
01:30Assembly of Signaling Complexes
6.8K
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,...
6.8K
01:22Activation and Inactivation of G Proteins
12.0K
Heterotrimeric G proteins are guanine nucleotide-binding proteins. As the name suggests, heterotrimeric G proteins are composed of three subunits: alpha, beta, and gamma. They remain GDP-bound or GTP-bound inside the cells and switch between inactive/active states. The Gα subunit possesses the nucleotide-binding pocket that binds guanine nucleotides and switches between GDP or GTP-bound states. In contrast, the Gꞵ and Gγ subunits are always bound together with high...
12.0K
01:15G Protein-coupled Receptors
18.5K
G Protein-Coupled Receptors or GPCRs are membrane-bound receptors that transiently associate with heterotrimeric G proteins and induce an appropriate response to sensory stimuli such as light, odors, hormones, cytokines, or neurotransmitters.
GPCRs are also called heptahelical, 7TM, or serpentine receptors, and consist of seven (H1-H7) transmembrane alpha-helices that span the bilayer to form a cylindrical core. The transmembrane helices are connected by three extracellular loops and three...
GPCRs are also called heptahelical, 7TM, or serpentine receptors, and consist of seven (H1-H7) transmembrane alpha-helices that span the bilayer to form a cylindrical core. The transmembrane helices are connected by three extracellular loops and three...
18.5K
01:30Transducer Mechanism: G Protein–Coupled Receptors
6.2K
G Protein–Coupled Receptors (GPCRs) are membrane-bound receptors that transiently associate with heterotrimeric G proteins and induce an appropriate response to various stimuli. GPCRs regulate critical physiological pathways and are excellent drug targets for treating diseases such as diabetes, cancer, obesity, depression, or Alzheimer's. Nearly 35% of approved drugs implement their therapeutic effects by selectively interacting with specific GPCRs.
GPCRs are also called heptahelical,...
GPCRs are also called heptahelical,...
6.2K
01:14Rab Proteins
5.3K
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...
5.3K