• Hormones are the body’s chemical messengers and are part of the endocrine system. Endocrine glands make hormones, which travel through the bloodstream to tissues and organs, and control most of our body’s major systems.

Signal Transduction

  • Signal transduction is the process by which a chemical or physical signal is transmitted through a cell as a series of molecular events, most commonly protein phosphorylation catalyzed by protein kinases, which ultimately results in a cellular response.


  • Epinephrine is a chemical that narrows blood vessels and opens airways in the lungs. These effects can reverse severe low blood pressure, wheezing, severe skin itching, hives, and other symptoms of an allergic reaction.


  • Progesterone is an endogenous steroid and progestogen sex hormone involved in the menstrual cycle, pregnancy, and embryogenesis of humans and other species. It belongs to a group of steroid hormones called the progestogens, and is the major progestogen in the body.


  • Receptors are chemical structures, composed of protein, that receive and transduce signals that may be integrated into biological systems.

Second Messengers

  • Are small molecules that do the work of communicating the information
  • Second messengers are molecules that relay signals received at receptors on the cell surface — such as the arrival of protein hormones, growth factors, etc. — to target molecules in the cytosol and/or nucleus.

G protein

  • G proteins, also known as guanine nucleotide-binding proteins, are a family of proteins that act as molecular switches inside cells, and are involved in transmitting signals from a variety of stimuli outside a cell to its interior.

Protein Kinase A

  • Protein Kinase A (PKA) is a protein that is dependent on cyclic AMP (cAMP) and without it, is deactivated. PKA is involved in signal-transduction pathways and phosphorylates proteins by adding a phosphate group. The molecule consists of two subunits, a regulatory subunit and a calalytic subunit. These subunits are inactive when cAMP is not bound. When cAMP binds to a regulatory subunit a conformational change occurs.

β-adrenergic Receptor Signaling

  • The beta-2 adrenergic receptor (β2 adrenoreceptor), also known as ADRB2, is a cell membrane-spanning beta-adrenergic receptor that interacts with (binds) epinephrine, a hormone and neurotransmitter (ligand synonym, adrenaline) whose signaling, via adenylate cyclase stimulation through trimeric Gs proteins, increased cAMP, and downstream L-type calcium channel interaction, mediates physiologic responses such as smooth muscle relaxation and bronchodilation.

Receptor Tyrosine Kinase

  • Receptor tyrosine kinases are the high-affinity cell surface receptors for many polypeptide growth factors, cytokines, and hormones. Of the 90 unique tyrosine kinase genes identified in the human genome, 58 encode receptor tyrosine kinase proteins.

Insulin Receptor

  • The Insulin Receptor is a type of tyrosine kinase receptor, in which the binding of an agonistic ligand triggers autophosphorylation of the tyrosine residues, with each subunit phosphorylating its partner.


  • RAS is a family of related proteins
  • Each is monomeric and like the a-subunit of G-proteins
  • RAS proteins bind guanine nucleotides
  • RAS swaps GDP for GTP on activation
  • Slowly cleaves GTP to GDP

Epidermal Growth Factor Receptor

  • The epidermal growth factor receptor is a transmembrane protein that is a receptor for members of the epidermal growth factor family of extracellular protein ligands.

Nerve Transmission

  • Relies on ion gradients and neurotransmitter molecules to transmit signal
  • Blocked by ion channel-blocking molecules


  • Prostanoids are a subclass of eicosanoids consisting of the prostaglandins (mediators of inflammatory and anaphylactic reactions), the thromboxanes (mediators of vasoconstriction), and the prostacyclins (active in the resolution phase of inflammation.)


  • It is a mutated gene whose activity can cause uncontrolled growth 


  • Unmutated form of an oncogene

HER2 Receptor

  • HER2 doesn’t require EGF binding for dimerization/activation
  • Is always signaling cell to divide when dimerized
  • Mutation increasing levels of HER2 found in several cancers (Breast Cancer, Ovarian Cancer, Stomach Cancer and Uterine Cancer)


  • BCR-ABL is a mutation that is formed by the combination of two genes, known as BCR and ABL. It’s sometimes called a fusion gene. The BCR gene is normally on chromosome number 22. The ABL gene is normally on chromosome number 9. The BCR-ABL mutation happens when pieces of BCR and ABL genes break off and switch places.