Intracellular Signaling

Intracellular signaling (also known as cell signaling) is the transmission of molecular signals from a cells exterior to its interior. Signals received by cells first interact with receptors on the cell surface which must be transmitted effectively into the cell. This is accomplished either by a series of biochemical changes within the cell or by modifying the cell membrane potential by the movement of ions in or out of the cell. Receptors that initiate biochemical changes can do so either directly via intrinsic enzymatic activities within the receptor or by activating intracellular messenger molecules.

Intracellular Signaling Product Areas

Signal Transduction Pathways

Signal transducing receptors are of four general classes:

  1. Receptors that penetrate the plasma membrane and have intrinsic enzymatic activity or are enzyme associated (Enzyme-linked Receptors)
  2. Receptors that are coupled, inside the cell, to G proteins (7-TM Receptors)
  3. Receptors that are found intracellularly and upon ligand binding directly alter gene transcription (Nuclear Receptors)
  4. Ligand-gated ion channels

The intracellular component of signal transduction is highly receptor specific, thereby maintaining the specificity of the incoming signal inside the cell. Signal transduction pathways amplify the incoming signal by a signaling cascade using a network of enzymes that act on one another in specific ways to ultimately generate a precise and appropriate physiological response by the cell. Signal transduction involves altering the behavior of proteins in the cascade, in effect turning them on or off like a switch. Adding or removing phosphates is a fundamental mechanism for altering the shape, and therefore the behavior, of a protein. Several small molecules within the cell act as intracellular messengers (also known as second messengers). These include cAMP, cGMP, nitric oxide, lipids and Ca2+ ions. Activated receptors stimulate second messenger production, which in turn activate other enzymes and so the cascade continues.

Physiology and Disease

One of the most important functions of cell signaling is to control and maintain normal physiological balance within the body. Activation of different signaling pathways leads to diverse physiological responses, such as cell proliferation, death, differentiation, and metabolism. In the last few years signal transduction therapy has become one of the most important areas of modern drug research. In a healthy organism, the processes of cellular growth and differentiation are tightly controlled, but in the pathological state, are uncoupled in such a way as to result in further damage-causing signals, or the growth of the malfunctioning cells. Proliferation of damaged or malfunctioning cells is often a key factor in the generation of disorders such as cancer, infectious diseases, inflammation, arteriosclerosis, arthritis and neurodegenerative diseases.

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Cancer Research Product Guide

Cancer Research Product Guide

Our Cancer Research Guide highlights over 750 products for cancer research. Request copy or view PDF today.

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Kinase Inhibitor Toolbox

80 Kinase inhibitors
pre-dissolved in DMSO

Kinase Inhibitor Toolbox

Includes many of the latest kinase inhibitors to become commercially available. Covers a wide range of kinase targets including EGFR, MAPK and CDK.

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Kinases Product Listing

Kinases Product Listing

Our Kinase listing highlights over 400 products for kinase research. Request copy or view PDF today.

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Programmed Cell Death

Written by Bram van Raam and Guy Salvesen

Programmed Cell Death Life Science Poster

Our Programmed Cell Death poster gives a summary of the signaling pathways involved in apoptosis, necroptosis and cell survival. Request copy or view PDF today.

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Estrogen Pathway

Estrogen Signaling Pathway

Estrogen controls many cellular processes including growth, differentiation and function of the reproductive system. View pathway or download PDF today.

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NF-κB Pathway

NF-κB Signaling Pathway

Signals through the NF-κB pathway are important in the inflammation and the adaptive and innate immune response. View pathway or download PDF today.

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MAPK Pathway

MAPK Signaling Pathway

The MAPK family kinases respond to extracellular stimuli such as heat and stress to mediate intracellular signals. View pathway or download PDF today.

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Wnt Pathway

Wnt Signaling Pathway

Signals through the Wnt pathway are fundamental for the regulation of cellular differentiation and proliferation. View pathway or download PDF today.

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VEGF Pathway

VEGF Signaling Pathway

VEGF signaling regulates vascular development (vasculogenesis) and the formation of new blood vessels (angiogenesis). View pathway or download PDF today.

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