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 Concept Videos

Amplifying Signals via Enzymatic Cascade01:22

Amplifying Signals via Enzymatic Cascade

When a ligand binds to a cell-surface receptor, the receptor's intracellular domain changes shape, which may either activate its enzyme function or allow its binding to other molecules. The initial signal is amplified by most signal transduction pathways. This means that a single ligand molecule can activate multiple molecules of a downstream target. Proteins that relay a signal are most commonly phosphorylated at one or more sites, activating or inactivating the protein. Kinases catalyze the...
PI3K/mTOR/AKT Signaling Pathway01:22

PI3K/mTOR/AKT Signaling Pathway

The mammalian target of rapamycin  (mTOR) is a serine/threonine kinase that regulates growth, proliferation, and cell survival in response to hormones, growth factors, or nutrient availability. This kinase exists in two structurally and functionally distinct forms: mTOR complex 1  (mTORC1) and mTOR complex 2  (mTORC2). The first form (mTORC1) is composed of a rapamycin-sensitive Raptor and proline-rich Akt substrate, PRAS40. In contrast,  mTORC2 consists of a rapamycin-insensitive companion...
Protein Kinases and Phosphatases02:54

Protein Kinases and Phosphatases

Proteins undergo chemical modifications that trigger changes in the charge, structure, and conformation of the proteins. Phosphorylation, acetylation, glycosylation, nitrosylation, ubiquitination, lipidation, methylation, and proteolysis are various protein modifications that regulate protein activity. Such modifications are usually enzyme-driven.
Protein kinases
Many proteins in the cell are regulated by phosphorylation, the addition of a phosphate group. A family of enzymes called kinases...
Protein Kinases and Phosphatases02:54

Protein Kinases and Phosphatases

Proteins undergo chemical modifications that trigger changes in the charge, structure, and conformation of the proteins. Phosphorylation, acetylation, glycosylation, nitrosylation, ubiquitination, lipidation, methylation, and proteolysis are various protein modifications that regulate protein activity. Such modifications are usually enzyme-driven.
Protein kinases
Many proteins in the cell are regulated by phosphorylation, the addition of a phosphate group. A family of enzymes called kinases...
Calmodulin-dependent Signaling01:16

Calmodulin-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,...
Phosphorylation01:02

Phosphorylation

The addition or removal of phosphate groups from proteins is the most common chemical modification that regulates cellular processes. These modifications can affect the structure, activity, stability, and localization of proteins within cells as well as their interactions with other proteins.
During phosphorylation, protein kinases transfer the terminal phosphate group of ATP to specific amino acid side chains of substrate proteins. Serine, threonine, and tyrosine are the most commonly...

You might also read

Related Articles

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

Sort by
Same author

Identification of Noncovalent Small-Molecules from Virtual Screening Toward the Development of Potential KRAS Inhibitors.

Journal of chemical information and modeling·2026
Same author

Synthesis and Biochemical Characterization of Investigational Pyrazolopyrimidine-Based Allosteric KRAS Modulators.

ACS medicinal chemistry letters·2026
Same author

Rap1b Activates Endosomal AC9 to Drive the Second cAMP Wave.

bioRxiv : the preprint server for biology·2026
Same author

MRTX1133 Suppresses ERK Signaling but Elicits Context-Dependent Antiproliferative Responses in KRAS (G12C) Cancer Cells.

Molecular cancer therapeutics·2026
Same author

Rheb membrane orientation dynamics and functional consequences elucidated by molecular simulations, single-molecule-FRET and signaling assays.

bioRxiv : the preprint server for biology·2026
Same author

MRTX1133 suppresses ERK signaling but elicits context-dependent antiproliferative responses in KRAS (G12C) cancer cells.

Molecular cancer therapeutics·2026

Related Experiment Video

Updated: Jun 21, 2026

Development and Application of Rapamycin-regulated Tyrosine Phosphatases
06:56

Development and Application of Rapamycin-regulated Tyrosine Phosphatases

Published on: September 6, 2024

Phosphorylation-induced conformational changes in Rap1b: allosteric effects on switch domains and effector loop.

Martin M Edreira1, Sheng Li, Daniel Hochbaum

  • 1Department of Pharmacology and Chemical Biology, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania 15261, USA.

The Journal of Biological Chemistry
|August 5, 2009
PubMed
Summary

Phosphorylation of Rap1b by protein kinase A (PKA) alters protein structure, affecting signaling pathways. This study used deuterium exchange mass spectrometry to reveal how phosphorylation at Ser(179) impacts Rap1b conformation and function.

More Related Videos

Spatio-Temporal Manipulation of Small GTPase Activity at Subcellular Level and on Timescale of Seconds in Living Cells
10:27

Spatio-Temporal Manipulation of Small GTPase Activity at Subcellular Level and on Timescale of Seconds in Living Cells

Published on: March 9, 2012

Oligopeptide Competition Assay for Phosphorylation Site Determination
09:16

Oligopeptide Competition Assay for Phosphorylation Site Determination

Published on: May 18, 2017

Related Experiment Videos

Last Updated: Jun 21, 2026

Development and Application of Rapamycin-regulated Tyrosine Phosphatases
06:56

Development and Application of Rapamycin-regulated Tyrosine Phosphatases

Published on: September 6, 2024

Spatio-Temporal Manipulation of Small GTPase Activity at Subcellular Level and on Timescale of Seconds in Living Cells
10:27

Spatio-Temporal Manipulation of Small GTPase Activity at Subcellular Level and on Timescale of Seconds in Living Cells

Published on: March 9, 2012

Oligopeptide Competition Assay for Phosphorylation Site Determination
09:16

Oligopeptide Competition Assay for Phosphorylation Site Determination

Published on: May 18, 2017

Area of Science:

  • Molecular Biology
  • Cell Signaling
  • Biochemistry

Background:

  • Rap1b is crucial for cAMP-mediated mitogenic responses.
  • cAMP-dependent protein kinase (PKA) phosphorylates Rap1b at Ser(179), impacting mitogenesis, tumorigenesis, and AKT activity.

Purpose of the Study:

  • To investigate the structural and dynamic changes in Rap1b induced by phosphorylation at Ser(179).
  • To elucidate the role of Ser(179) phosphorylation in Rap1b's allosteric communication with effector domains.

Main Methods:

  • Amide hydrogen/deuterium exchange mass spectrometry (DXMS) was employed.
  • DXMS was used to compare the exchange rates of PKA-phosphorylated Rap1b (Rap1-P) and S179D phosphomimetic Rap1b (Rap1-D).

Main Results:

  • Phosphorylated Rap1b (Rap1-P) and the phosphomimetic Rap1-D exhibited identical behavior in DXMS.
  • Increased deuterium exchange rates were observed in regions near Ser(179) and in the switch loops, indicating altered dynamics.
  • These changes suggest allosteric communication between the phosphorylation site and distal effector-binding domains.

Conclusions:

  • Ser(179) phosphorylation induces conformational and dynamic changes in Rap1b.
  • These allosteric effects provide a mechanistic basis for PKA-mediated regulation of Rap1b effector interactions and downstream signaling.