Cyclic adenosine monophosphate

In which cyclic adenosine monophosphate is a molecule that arises from adenosine triphosphate from a biochemical point of view. The cyclic adenosine monophosphate is used in many cases only with the abbreviation cAMP designated. The molecule acts as a so-called second messenger in the context of signal transduction by cells. The primary purpose of the cyclic adenosine monophosphate is to activate certain types of protein kinases.

What is cyclic adenosine monophosphate?

In principle, cyclic adenosine monophosphate is a special signal substance which, from a chemical point of view, belongs to the category of nucleotides. In the context of numerous signal cascades that are related to the effects of hormones and metabolism, the molecule takes on the function of a second messenger. The cyclic adenosine monophosphate has a molar mass of 329.21 grams per mole.

The cyclic adenosine monophosphate has important functions in regulating the metabolism. Because the molecule activates the protein kinases, a regulation of many metabolic functions takes place. An example of this is the breakdown of glycogen into glucose. The cyclic adenosine monophosphate also plays an important role with regard to lipolysis and the release of tissue hormones such as somatostatin.

Function, effect & tasks

The cyclic adenosine monophosphate is characterized by a multitude of important functions and effects in the organism. Therefore, the molecule plays an important role in a functioning metabolism and general human health.

The cyclic adenosine monophosphate is particularly relevant for the activation of protein kinases. The molecule primarily activates type A protein kinases. As a result of phosphorylation, these substances develop numerous effects. For example, they lead to phosphorylation of calcium ion channels. As a result, the corresponding channels open. In addition, they also cause the so-called myosin light chain kinases to be phosphorylated. This relaxes the smooth muscles.

At the same time, the sensitivity of the corresponding muscles to calcium ions is reduced. It should be noted, however, that the current status of medical research has not conclusively clarified whether this mechanism of action is relevant in vivo. The cyclic adenosine monophosphate also leads to a phosphorylation of certain transcription factors, for example CREB. This causes genes induced by the cyclic adenosine monophosphate to also be transcribed. In addition, the cyclic adenosine monophosphate also fulfills numerous important functions in bacteria, which in turn can be related to the human organism and are relevant to it.

In bacteria, the cyclic adenosine monophosphate acts as a so-called hunger signal or glucose deficiency signal. However, it shows a completely different mechanism of action. The substance plays an important role in the repression of glucose and the utilization of lactose and the associated control system. If glucose is in the appropriate medium, the genes of the so-called lactose operon are switched off. This effect makes sense because the utilization of the lactose in this case is too time-consuming and unnecessary.

If glucose is present, the cyclic adenosine monophosphate usually has only a low concentration. If, on the other hand, the glucose is withdrawn, the concentration increases by activating a bacterial adenylyl cyclase. A certain transport protein is phosphorylated. This connects to another molecule and activates it. The cyclic adenosine monophosphate then binds to the so-called catabolite activator protein. This is also called the cAMP receptor protein. The protein activates the transcription factor of the corresponding gene. As a result, the intake of lactose begins under starvation conditions.

Education, occurrence, properties & optimal values

The cyclic adenosine monophosphate is synthesized and metabolized under special conditions. The formation of the molecule takes place in numerous human cells in the body after the substance binds to certain signal molecules or G-protein-coupled receptors. The alpha subunit of the G protein is activated. As a result, the adenylate cyclase forms the cyclic adenosine monophosphate from the ATP. In the process, pyrophosphate is split off and the remaining phosphate group is esterified with another ribose group. When broken down, this ester bond is cleaved by the enzyme phosphodiesteras.

If a certain receptor is activated by a hormone such as glucagon, an odorous substance or neurotransmitter such as norepinephrine, a membrane-bound adenylyl cyclase is stimulated. This is responsible for the conversion of cellular ATP into the cyclic adenosine monophosphate. Forskolin is known to directly stimulate adenylyl cyclase. The enzyme phosphodiesterase plays an important role as a catalyst in the breakdown of cyclic adenosine monophosphate to adenosine monophosphate. Caffeine has an inhibiting effect on the enzyme.

Diseases & Disorders

Since the cyclic adenosine monophosphate assumes important functions, for example in the regulation of metabolic processes in the human organism, disturbances have a correspondingly serious effect. The cyclic adenosine monophosphate is an important molecule with mediating functions, especially for hormone metabolism.

The cyclic adenosine monophosphate primarily contributes to the activation of enzymes inside cells. These enzymes play an important role in the metabolism of proteins. If the synthesis or transmission of the cyclic adenosine monophosphate is disturbed, the corresponding metabolic processes no longer run correctly, which, depending on the metabolic process concerned, affects health and requires endocrinological therapy.