Rap1 plays role in smooth muscle cell vasoconstriction

August 6, 2012
Rap1 plays role in smooth muscle cell vasoconstriction
The Ras-related small GTPase, Rap1, couples to RhoA, and is involved in relocalization of G protein-coupled α2C-adrenoceptors in smooth muscle cells derived from human dermal arterioles, according to a study published online May 23 in the American Journal of Physiology -- Cell Physiology.

(HealthDay) -- The Ras-related small GTPase, Rap1, couples to RhoA, and is involved in relocalization of G protein-coupled α2C-adrenoceptors (α2CARs) in smooth muscle cells derived from human dermal arterioles (microVSM), according to a study published online May 23 in the American Journal of Physiology -- Cell Physiology.

Noting that α2C-ARs mobilize to the cell surface and elicit vasoconstriction in response to cellular stress, Selvi C. Jeyaraj, Ph.D., from the Research Institute at Nationwide Children's Hospital in Columbus, Ohio, and colleagues used microVSM to examine the role of Rap1 in α2C-AR receptor localization.

The researchers found that, in human microVSM, increasing intracellular cyclic adenosine monophosphate activated RhoA, increased α2C-AR expression, and increased F-actin via reorganization of the actin cytoskeleton. The α2C-ARs were mobilized to intracellular filamentous structures and to the plasma membrane, from the perinuclear region. In murine wild-type microVSM there were similar results, coupling Rap1-Rho-actin dynamics to receptor relocalization. In Rap1A-null murine microVSM, this signaling was impaired, and it was rescued by delivery of a constitutively-active (CA) Rap1A mutant. Rap1A-CA or Rho-kinase caused translocation of functional α2C-ARs to the cell surface.

"In summary, our results show Rap1 coupling to RhoA activation and reorganization of the actin cytoskeleton, necessary for translocation of microVSM α2C-ARs," the authors write. "The exact mechanism for α2C-AR translocation by actin remains to be determined and is the focus of ongoing work."

Explore further: Are cold feet plaguing your relationship? Physiologists identified biological mechanism that could be responsible

More information: Abstract
Full Text

Related Stories

Are cold feet plaguing your relationship? Physiologists identified biological mechanism that could be responsible

July 31, 2012
Cold feet -- those chilly appendages that plague many people in the winter and an unlucky few all year round -- can be the bane of existence for singles and couples alike. In a new study, scientists led by Selvi C. Jeyaraj ...

Hypoferremia predicts treatment response to IFN-α

March 1, 2012
(HealthDay) -- For patients with hepatitis C virus (HCV), hepcidin, a regulator of iron homeostasis, is induced following a single dose of pegylated interferon-α (PEG-IFNα), and may be a surrogate marker of immediate ...

Study first to link mitochondrial dysfunction and alpha-Synuclein multiplication in human fibroblasts

October 6, 2011
A new study in the Journal of Parkinson's Disease shows for the first time the effects of α-Synuclein (α-syn) gene multiplication on mitochondrial function and susceptibility to oxidative stress in human tissue. ...

New research reveals how alpha-synuclein interacts with cell membranes in Parkinson's disease

January 18, 2012
The accumulation of α-synuclein, a small, negatively charged protein, in neural cells, is one of the hallmarks of Parkinson's disease. It has been suggested that oligomeric α-synuclein causes membranes to become ...

Seeds of destruction in Parkinson's disease: Spread of diseased proteins kills neurons

October 5, 2011
New research suggests that small "seed" amounts of diseased brain proteins can be taken up by healthy neurons and propagated within them to cause neurodegeneration. The research, published by Cell Press in the October 6 issue ...

Recommended for you

Scientists find key to regenerating blood vessels

November 23, 2017
A new study led by researchers at Sanford Burnham Prebys Medical Discovery Institute (SBP) identifies a signaling pathway that is essential for angiogenesis, the growth of new blood vessels from pre-existing vessels. The ...

Researchers find infectious prions in Creutzfeldt-Jakob disease patient skin

November 22, 2017
Creutzfeldt-Jakob disease (CJD)—the human equivalent of mad cow disease—is caused by rogue, misfolded protein aggregates termed prions, which are infectious and cause fatal damages in the patient's brain. CJD patients ...

Surprising roles for muscle in tissue regeneration, study finds

November 22, 2017
A team of researchers at Whitehead has illuminated an important role for different subtypes of muscle cells in orchestrating the process of tissue regeneration. In a paper published in the November 22 issue of Nature, they ...

Study reveals new mechanisms of cell death in neurodegenerative disorders

November 22, 2017
Researchers at King's College London have discovered new mechanisms of cell death, which may be involved in debilitating neurodegenerative disorders, such as Alzheimer's disease and Parkinson's disease.

Cinnamon turns up the heat on fat cells

November 21, 2017
New research from the University of Michigan Life Sciences Institute has determined how a common holiday spice—cinnamon—might be enlisted in the fight against obesity.

How rogue immune cells cross the blood-brain barrier to cause multiple sclerosis

November 21, 2017
Drug designers working on therapeutics against multiple sclerosis should focus on blocking two distinct ways rogue immune cells attack healthy neurons, according to a new study in the journal Cell Reports.

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.