Cellular Signaling

sending and receiving molecular messages

Cells are in constant communication, deciding when to grow, whether dangers are present, and whether they should move to new environments. They talk to one another by sending small messenger molecules, which are received by receptor molecules on their cell surfaces. Atomic structures have revealed both these signaling molecules and their receptors.

Molecule of the Month Articles (43)

	Acetylcholine Receptor The neurotransmitter acetylcholine opens a protein channel, stimulating muscle contraction
	Acetylcholinesterase Acetylcholinesterase stops the signal between a nerve cell and a muscle cell
	Adrenergic Receptors Adrenaline stimulates a G-protein-coupled receptor, priming us for action
	AMPA Receptor Receptors for the neurotransmitter glutamate in our brain come in several shapes and sizes.
	Anabolic Steroids Anabolic steroids like testosterone are among the most common performance enhancing drugs
	Auxin and TIR1 Ubiquitin Ligase The plant hormone auxin controls growth and response to light and gravity
	Calcium Pump Atomic structures have captured the calcium pump in action
	Calmodulin Calcium ions rapidly deliver signals to control processes such as muscle contraction, nerve signaling, and fertilization
	cAMP-dependent Protein Kinase (PKA) PKA delivers cellular signals by adding phosphates to proteins
	Cyclin and Cyclin-dependent Kinase Cyclins and cyclin-dependent kinases control when cells divide, making them important targets for cancer therapy.
	Cyclooxygenase Aspirin attacks an important enzyme in pain signaling and blood clotting
	Designer Insulins Engineered insulins have been developed to improve treatment of diabetes
	Dipeptidyl Peptidase 4 Inhibitors of dipeptidyl peptidase 4 are used to treat type-2 diabetes
	Epidermal Growth Factor EGF is part of a family of proteins that controls aspects of cell growth and development
	Estrogen Receptor Estrogen binds to receptors in the nucleus and affects key genes in development
	G Proteins Trimeric G-proteins receive signals from cellular receptors and deliver them inside the cell
	Glucagon Glucagon triggers the release of glucose into the blood, to power cells throughout the body
	Glutamate-gated Chloride Receptors The antibiotic ivermectin attacks glutamate-gated chloride channels, paralyzing parasitic worms.
	Growth Hormone Growth hormone brings together two copies of its cellular receptor
	Insulin The hormone insulin helps control the level of glucose in the blood
	Insulin Receptor The cellular receptor for insulin helps control the utilization of glucose by cells
	Interferons Interferons mobilize defenses against viral infection
	Leptin Problems with the appetite-controlling hormone leptin can lead to obesity
	Mechanosensitive Channels Pressure-sensitive channels open when the internal pressure of a cell gets too high
	Neurotransmitter Transporters Neurotransmitters are transported out of nerve synapses to end a signal transmission
	Neurotrophins Neurotrophins guide the development of the nervous system
	Nitric Oxide Synthase Nitric oxide gas is used as a rapid-acting hormone and as a powerful defense
	Opioid Receptors Morphine and other opioid drugs bind to receptors in the nervous system, controlling pain
	PD-1 (Programmed Cell Death Protein 1) PD-1 and its ligands are a new target for cancer therapy
	Photoactive Yellow Protein Researchers use synchrotrons and X-ray lasers to reveal the rapid processes of light sensing.
	Phototropin Phototrophins sense the level of blue light, allowing plants to respond to changing environmental conditions
	Piezo1 Mechanosensitive Channel Mechanosensitive ion channels give our cells a sense of touch.
	Potassium Channels Potassium channels allow potassium ions to pass, but block smaller sodium ions
	RAF Protein Kinases A single mutation in a RAF protein kinase can help transform a normal cell into a cancer cell.
	Ras Protein Mutation of the growth-contolling ras protein can lead to cancer
	Receptor for Advanced Glycation End Products RAGE recognizes sugar-modified proteins, contributing to an inflammatory response that plays a role in diabetes
	Rhodopsin In our eyes, rhodopsin uses the molecule retinal to see light
	Serotonin Receptor Serotonin receptors control mood, emotion, and many other behaviors, and are targets for many important drugs
	SNARE Proteins SNARE proteins power the fusion of vesicles with membranes by forming a bundle of alpha helices
	Src Tyrosine Kinase Growth signaling proteins play an important role in the development of cancer
	Tissue Factor Tissue factor senses damage to the body and triggers formation of a blood clot
	Two-component Systems Bacteria respond to their environment with two-component sensing systems.
	Vitamin D Receptor Vitamin D helps regulate the use of calcium throughout the body

Learning Resources (6)

G Protein-Coupled Receptor (GPCR)

G-Protein Coupled Receptors

(Flyer)

Cell Signaling: A Molecular View

Structural Biology Highlights (15)

Global Health (1)

Diabetes Mellitus - Insulin Receptor

Goodsell Molecular Landscapes (1)

Insulin Action

	G Protein-Coupled Receptor (GPCR) Paper Model GPCRs are a large family of membrane-embedded receptors, with structural features that have been preserved through the course of evolution. This model represents the shared structural features of all GPCRs. With the extracellular N-terminus, the protein chain folds to form a bundle of seven transmembrane alpha helices connected by 3 intracellular and 3 extracellular loops with the C-terminus reaching inside the cell.
	Insulin Paper Model Learn about insulin, a peptide hormone that plays a critical role in our ability to use glucose from the food that we eat
	Insulin and Diabetes Poster Structural biology has revealed the details of insulin signaling and how this knowledge is being used to create new and better treatments for diabetes.
	G-Protein Coupled Receptors Flyer In honor of the 2012 Nobel Prize in Chemistry.
	Photoactive Yellow Protein and XFEL/SFX GIF Structures of photoactive yellow protein were determined by serial femtosecond crystallography after illumination, capturing the isomerization of the chromophore after it absorbs light. Structures included in this movie include: 5hd3 (ground state), 5hdc (100-400 femtoseconds after illumination), 5hdd (800-1200 femtoseconds), 5hds (3 picoseconds), 4b9o (100 picoseconds), 5hd5 (200 nanoseconds) and 1ts0 (1 millisecond). For more, see the Molecule of the Month on Photoactive Yellow Protein and Guide to Understanding PDB Data: Methods for Determining Atomic Structures
	Calcium Pump Video The calcium pump moves ions across cell membranes allowing the synchronized contraction of muscle cells.