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

Researchers illustrate how muscle growth inhibitor is activated, could aid in treating ALS

January 19, 2018
Researchers at the University of Cincinnati (UC) College of Medicine are part of an international team that has identified how the inactive or latent form of GDF8, a signaling protein also known as myostatin responsible for ...

Bioengineered soft microfibers improve T-cell production

January 18, 2018
T cells play a key role in the body's immune response against pathogens. As a new class of therapeutic approaches, T cells are being harnessed to fight cancer, promising more precise, longer-lasting mitigation than traditional, ...

Weight flux alters molecular profile, study finds

January 17, 2018
The human body undergoes dramatic changes during even short periods of weight gain and loss, according to a study led by researchers at the Stanford University School of Medicine.

Secrets of longevity protein revealed in new study

January 17, 2018
Named after the Greek goddess who spun the thread of life, Klotho proteins play an important role in the regulation of longevity and metabolism. In a recent Yale-led study, researchers revealed the three-dimensional structure ...

The HLF gene protects blood stem cells by maintaining them in a resting state

January 17, 2018
The HLF gene is necessary for maintaining blood stem cells in a resting state, which is crucial for ensuring normal blood production. This has been shown by a new research study from Lund University in Sweden published in ...

Magnetically applied MicroRNAs could one day help relieve constipation

January 17, 2018
Constipation is an underestimated and debilitating medical issue related to the opioid epidemic. As a growing concern, researchers look to new tools to help patients with this side effect of opioid use and aging.

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.