Help
Options
Didn't know it?
click below
click below
Knew it?
click below
click below
Don't Know
Remaining cards (0)
Know
retry
shuffle
restart
0:00
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.
Normal Size Small Size show me how
Normal Size Small Size show me how
ODSC 6A
| Question | Answer |
|---|---|
| I. General Principles of Signaling | |
| Signal transduction | refers to the movement of signals from outside to inside |
| Involves | ligand/receptor interaction, phosphorylation, kinases, amplification |
| Ligand binds to | receptor, ligand gives off signal |
| General Idea | |
| Slide 4Ligan/receptor interaction | |
| Types of signaling | autocrine, paracrine, endocrine |
| 1. Autocrine | molecules act on themselves |
| Ex | IL 2 and ostepontin |
| 2. Paracrine | (proxy)act on cells nearby |
| 3. Endocrine | act on cells far away |
| Ex | hormones |
| 4. Synaptic signaling | neurotransmitter released at the nerve terminal |
| II. Different types of signaling molecules or ligands | |
| 1. Hormones: Cortisol, estradiol, glucagon, insulin, testosterone, thyroid hormone | |
| 2. Growth factors: EGF, PDGF, NGF, TGF | beta |
| 3. Local mediators: Nitric oxide, Histamine | |
| 4. Extracellular matrix proteins: Collagen, Osteopontin, vitronectin, fibronectin | |
| 5. Neurotransmitters: Acetylcholine, g | Aminobutyric acid |
| Some molecules do NOT fit into one type ex | epinephrine which acts as hormone and neurotransmitter |
| III. How receptors relay signals via intracellular signaling | |
| Cellular signaling cascade can follow a | complex path |
| Receptor/ligand interaction activates | intracellular proteins that amplify the signals |
| Steps involved in signal transduction | |
| 1. Ligand binds to receptor | |
| 2. Signal cascade transfers signals into cell | |
| 3. Cascade is continued by other intracellular molecules | |
| 4. Cascade triggers response ex; divide | |
| Amplification of cell survival(anti apoptotic) signal by phosphorylatino and activation of akt | |
| IV. Different classes of receptors | |
| Extracellular receptors | on surface of the cell |
| Intracellular receptors | inside the cell in cytoplasm ex, steroids |
| Categories of Cell surface receptors | |
| Types of Receptors | ion, growth factor, G protein, integrin, steroid |
| 1. Receptors with No tyrosine kinase activity | have No kinases so recruit other receptors that have kinase activity |
| 2. Receptor Tyrosine kinase | have tyrosine kinase activity |
| Activation induces | dimerization and autophosporylation which stimulates activity of intracellular kinases |
| 3. Receptor Serine/threonine kinase | Transforming growth factor |
| Intracellular receptors | steroid receptor |
| 1. Steroid receptor | can cross plasma membrane and bind to receptors in the cytoplasm or on the nuclease |
| V. Intracellular proteins that act as molecular switches | |
| Kinases mediate | protein phosphorylation |
| Phosphatases removes | the phosphate group by hydrolysis |
| Kinases and phosphatases act as | molecular switches |
| Phosphorylation | most common posttranslational modification and mediate protein dephosphorylation |
| Intrinsic enzymatic activity | all can autophosphorylate, ex tyrosine kinases, tryosine phosphatases, serine/threonine |
| VI. Role of second messengers in the intracellular signaling | |
| Secondary messenger refers to an | intracellular signaling molecule that is downstream from the receptor |
| Examples of second messengers | Camp, IP3, DAG, metabolites of arachidonic acid, nitric oxide |
| Best characterized second messengers is | cAMP (cyclic AMP) |
| G protein | largest family of cell surface receptors, secondary messenger (homodimer) |
| Structure | polypeptide snakes through membrane 7 times |
| Trimeric G proteins | disassemble to relay signals from G proteins |
| Integration of multiple pathways | |
| Synergestic | two individual signals both activate the same protein at two different sites |
| Converge | two individual signals phosphorylate two different proteins which signals for active protein |
| VII. Protein, Protein interactions and modular domain | |
| Interactions are | complex interactions between signaling proteins |
| Mediated by | modular domains |
| Modular domains | specific/unique amino acid sequence |
| Common modular domains | SH2 SH3 PH |
| Role of Modular domains | mediate interaction between receptor and signaling proteins and also between signaling proteins inside the cell |
| VIII. Kinases and possible therapeutic targets for cancer | |
| Fluorosis | hypomineralization of teeth alters kinase and phosphatase activity |
| Enzymes such as kinase and phosphoratase can be used as | drug targets for protein inhibitors |
| Bisphosphonates | drugs that prevent and treat cancer induced osteoporosis by inhibiting osteoclasts |
Created by:
mcap
Popular Biology sets