Second messengers


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Second messengers

Molecules used to transmit signals within cells. These molecules trigger a cascade of events by activating other cellular components. The ability of cells to respond to specific extracellular molecules, or agonists, is crucial to growth, development, and homeostasis of multicellular organisms. Signal transduction refers to the movement of a signal initiated outside the cell into the cell interior. Many agonists induce the stimulation of cell growth, differentiation, or expression of specific genes. Signal transduction pathways must, therefore, include mechanisms for the initiation of signals at the cell surface membrane (plasma membrane), as well as a mechanism by which these signals traverse the interior of the cell (cytoplasm), and induce the desired target response. The pathways involve cascades of sequential molecular activation steps that are organized into three major components: (1) a receptor that recognizes and binds agonists, (2) second messengers, or signal transducing molecules, that couple receptors to intracellular pathways, and (3) effectors or molecules responsible for the ultimate response. A central feature of all signaling cascades is that they discriminate among a variety of signals and provide a mechanism for signal amplification. See Signal transduction

References in periodicals archive ?
Or the primary effector may trigger the production of another signaling chemical, called the second messenger, within the cell.
Inositol plays a fundamental role in the cell in two different manners: (1) incorporated in membrane phospholipids, producing phosphoinositides upon membrane receptor stimulation [41] and (2) in form of inositolphosphoglycans (IPG) that can be located at the inner or outer side of the plasma membrane and are involved in insulin transduction signaling as second messengers [42].
Further exploration of the role of calcium second messengers and light transduction in corals will allow a variety of biological processes to be better understood.
Cyclic AMP (CAMP): Second messenger molecule whose production by enzymes called adenylyl cyclases is regulated through receptor activation of G -proteins, and which itself activates certain protein kinases.
His text includes a discussion on the extracellular activity of neurons, and, briefly, on their intracellular functions, known as the second messenger system.
Many hormones require second messengers to effect their molecular message.
2] and generation of two key intracellular second messengers, [IP.
Robert McNamara is author of Second Messengers (Wesleyan UP, 1990)
The pathogen also activates host PLC upon bacterial contact, leading to the production of two second messengers, which further initiate signaling events (42).
Gilman at the University of Texas Southwestern Medical Center at Dallas share this year's Nobel Prize in Physiology or Medicine for identifying G proteins, which translate and integrate external signals for the cell's second messengers.
Section I: Biophysical Chemistry, Metabolism, Second Messengers, and Ultrastructure
Nucleotide second messengers are key components of the signal transduction networks that