What does Epac do?
The major function of Epac is to serve as the guanine nucleotide exchange or GEF function for Rap1 and Rap2. Epac and Rap play major roles in the regulation of cardiac function, secretion, vascular function, proliferation, and inflammation and study of these processes has revealed downstream targets (1).
How does cAMP activate EPAC?
Epac proteins bind to cAMP with high affinity and activate the Ras superfamily small GTPases Rap1 and Rap2. Rap1 was initially identified as an antagonist for the transforming function of Ras [43]. Rap1 can be activated in response to a variety of second messengers including cAMP [45].
What protein does cAMP activate?
protein kinase A
Importance. In humans, cAMP works by activating protein kinase A (PKA, cAMP-dependent protein kinase), one of the first few kinases discovered. It has four sub-units two catalytic and two regulatory. cAMP binds to the regulatory sub-units.
What are exchange proteins?
Exchange proteins directly activated by cAMP, or Epacs, are a recently discovered family of signalling proteins that bind cAMP and activate the small Ras-related monomeric G proteins Rap1 and Rap2 (de Rooij et al. 1998; Kawasaki et al. 1998; Bos, 2006).
What happens during the first step in the signal transduction pathway involving cAMP?
Adenylyl cyclase synthesizes cAMP from ATP. In the first step of the signal transduction pathway involving cAMP, a signal molecule binds to and activates a receptor called 1.
What happens when cAMP levels are high?
Cyclic AMP (cAMP) is an intracellular second messenger to a wide variety of hormones and neurotransmitters. In T cells, elevated cAMP levels antagonize T cell activation by inhibiting T cell proliferation and by suppressing the production of IL-2 and IFN-γ.
What is adenylyl cyclase?
Adenylyl cyclase is the enzyme that synthesizes cyclic adenosine monophosphate or cyclic AMP from adenosine triphosphate (ATP). Cyclic AMP functions as a second messenger to relay extracellular signals to intracellular effectors, particularly protein kinase A.
What are the three stages of signal transduction?
In effect, signal transduction is said to have three stages: First, reception, whereby the signal molecule binds the receptor. Then, signal transduction, which is where the chemical signal results in a series of enzyme activations. Finally, the response, which is the resulting cellular responses.
What happens when cAMP is decreased?
This was shown via a series of mutations in cAMP pathway components that would increase cAMP levels that result in increased wake behavior; conversely, mutations that result in decrease in cAMP levels result in increased sleep. In mice, knockout of two CREB isoforms results in reduced wakefulness.