Related Experiment Video

Updated: May 31, 2026

Characterize Disease-related Mutants of RAF Family Kinases by Using a Set of Practical and Feasible Methods
07:49

Characterize Disease-related Mutants of RAF Family Kinases by Using a Set of Practical and Feasible Methods

Published on: July 17, 2019

Clinically observed RASA1 missense mutants exhibit diverse RasGAP protein behaviors in vitro

Maxum E Paul1, Rediet B Delelegne2, Jocelyn E Chau1

  • 1Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut, USA.

The Journal of Biological Chemistry
|May 28, 2026
PubMed

Insights

Mutations in the RASA1 gene, linked to cerebrovascular disorders and cancer, disrupt RasGAP protein function through various mechanisms. Understanding these disease-associated mutations provides insights into signaling pathway dysregulation.

Area of Science:

  • Genetics and Molecular Biology
  • Biochemistry
  • Cell Signaling

Background:

  • The RASA1 gene encodes the RasGAP (p120RasGAP) protein, crucial for regulating cellular signaling.
  • Mutations in RASA1 are associated with cerebrovascular disorders and various cancers.
  • The precise mechanisms by which RASA1 mutations dysregulate RasGAP signaling are not fully understood.

Purpose of the Study:

  • To catalogue disease-associated RASA1 mutations.
  • To investigate the impact of these mutations on RasGAP protein function in vitro.
  • To classify the modes of dysregulation caused by RASA1 mutations.

Main Methods:

  • Mapping disease-associated mutations onto structural models of RasGAP.
  • Assessing the effects of key mutations on protein expression, thermal stability, and p190RasGAP interaction.
  • Evaluating the Michaelis-Menten kinetics of mutant RasGAP proteins towards Ras.

Main Results:

  • Disease-associated RasGAP mutations were classified into distinct categories based on their dysregulation mechanisms.
  • Protein stability was found to be necessary but not sufficient for full RasGAP catalytic activity.
  • Destabilizing mutations across the protein disrupt RasGAP function, while the C2 domain uniquely regulates activity via residue interactions, independent of stability.

Conclusions:

  • RASA1 mutations contribute to disease through diverse mechanisms affecting RasGAP function.
  • RasGAP protein stability is critical for its catalytic activity, but other regulatory mechanisms also exist.
  • The C2 domain plays a distinct role in modulating RasGAP activity, highlighting specific structural contributions to signaling regulation.
Keywords:
CM-AVMGTP hydrolysisGTPase activating proteinRASA1cancerp120RasGAPras signalingvein of Galen malformation

More Related Videos

Fully Processed Recombinant KRAS4b: Isolating and Characterizing the Farnesylated and Methylated Protein07:08

Fully Processed Recombinant KRAS4b: Isolating and Characterizing the Farnesylated and Methylated Protein

Published on: January 16, 2020

Related Concept Videos

The Ras Gene02:38

The Ras Gene

The Ras-gene-encoded proteins are regulators of signaling pathways controlling cell proliferation, differentiation, or cell survival. The Ras-gene family in humans constitutes three primary members—the HRas, NRas, and KRas. These genes code for four functionally distinct yet closely related proteins—the HRas, NRas, KRas4A, and KRas4B. The involvement of mutant Ras genes in human cancer was first discovered in 1982 and is among the most common causes of human tumorigenesis.
Ras is a superfamily...
Small GTPases - Ras and Rho01:24

Small GTPases - Ras and Rho

Ras and Rho are small monomeric GTPases that act downstream of receptor tyrosine kinase (RTK) and regulate various cellular processes. These GTPases switch between active and inactive states by binding to guanine nucleotides.
Three regulatory proteins control their activity:
The Ras Gene02:38

The Ras Gene

The Ras-gene-encoded proteins are regulators of signaling pathways controlling cell proliferation, differentiation, or cell survival. The Ras-gene family in humans constitutes three primary members—the HRas, NRas, and KRas. These genes code for four functionally distinct yet closely related proteins—the HRas, NRas, KRas4A, and KRas4B. The involvement of mutant Ras genes in human cancer was first discovered in 1982 and is among the most common causes of human tumorigenesis.
Ras is a superfamily...
Rab Cascades01:25

Rab 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.
Rab Proteins01:14

Rab 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...
MAPK Signaling Cascades01:07

MAPK Signaling Cascades

Mitogen-activated protein kinase, or MAPK pathway, activates three sequential kinases to regulate cellular responses such as proliferation, differentiation, survival, and apoptosis. The canonical MAPK pathway starts with a mitogen or growth factor binding to an RTK. The activated RTKs stimulate Ras, which recruits Raf or MAP3 Kinase (MAPKKK), the first kinase of the MAPK signaling cascade. Raf further phosphorylates and activates MEK or MAP2 Kinases (MAPKK), which in turn phosphorylates MAP...