Biosignaling German (9/15/16) Flashcards
What are the four components of signal transduction?
Signal
Receptor
Transduction pathways
Targets
What are three major types of signals that can occur?
Soluble
Linked
Physical
What are three types of soluble signals?
Proteins amd Amino Acids
Lipids and Fatty Acids
Carbohydrates
What is an example of a linked signal?
Integrin
What are some examples of physical signals?
Mechanical
Light
Temperature
What are the seven types of receptor families?
GPCR Receptor Tyrosine Kinase Receptor Guanylyl cyclase Ligand gated ion channels Adhesion Nuclear Cytokine
T/F the ligand concentration dramatically impact signaling?
True
What kind of receptor binding initiates signal transduction?
Ligand-receptor
What is the dissociation constant?
Kd = [L][R] divided by [LR]
What are the four roles that the plasma membrane has an active role in signaling?
Receptor localization
Ligand exposure
Signaling complex formation
Endocytosis
What are the four broad scales that signaling occurs over?
Autocrine
Paracrine
Synaptic
Endocrine
What is autocrine signaling?
Self stimulating signal (very local)
What is synaptic signaling?
Small scale local signaling (nervous)
What is paracrine signaling?
Signaling within organ systems local or between organs
What is endocrine signaling?
Released signal goes into vasculature
What complex formation to membranes allow in signaling?
Protein Scaffolds
Signaling Endosomes
What are the two types of lipid rafts?
Caveolar
Planar
What pathway sorts internalize vesicles?
The endocytic pathway
What is the critical protein in the endocytic pathway?
Rab GTPase
Where does the pH initially drop in the endocytic pathway?
Early endosome
Where does the pH drop after the Early endosome?
The late endosome
What does the change in pH do to the ligand binding?
It causes the ligand to stop binding
What are the 2 pathways from the early endosome?
Recycling
Late
What protein directs the vesicles in the endocytic pathway?
Rab GTPase
T/F the Endocytic pathway spatially and temporally regulates signaling
True
What are the 7 steps in signal transduction?
First messenger receptor signal transducer primary effector second messenger secondary effector signaling cascade
What are first messengers in general?
Neurotransmitter
What is metabotropic NT receptors an exmaple of?
Receptors
What is an G-protein an example of?
signal transducer
What is Adenylyl cyclase an example of?
Primary effector
What is Cyclic AMP an example of?
Second messenger
What is Protein Kinase A an example of?
Secondary effector
What are three ways that chemical reactions transfer information?
Complex formation/dissociation
Structural Change
Post-translational modification
What are 7 examples post translation modifications?
Phosphorylation Ubiquitination Glycosylation Oxidation Methylation Acetylation SUMOylation
What are 4 common signaling cascades?
MAPK
JAK-STAT
PI3K
PLC
T/F Receptors activate multiple signaling cascades.
True
What is the first step of the MAPK signaling pathway?
GTP activated RAS activates MAP kinase kinase kinase
What is the second step of the MAPK signaling pathway?
MAP kinase kinase
What is the third step of the MAPK signaling pathway?
MAP kinase
What is the fourth step of the MAPK pathway?
The activation of transcription factors
What is the first step of the JAK-STAT pathway?
The receptor dimerizes
What is the second step of the JAK-STAT pathway?
The Janus kinase is recruited by the dimerized receptor
What is the third step of the JAK-STAT pathway?
The janus kinase phosphorylates 2 places
What is the first place that the janus kinase phosphorylates?
The tail
Once the tail is phosphorylated in the JAK-STAT pathway what occurs?
STAT is brought to the complex
What is the second place that janus kinase phosphorylates?
STAT
What is the fourth step of the JAK-STAT pathway?
STAT goes to the nucleus.
Which pathway phosphorylates a lipid (PIP2 to PIP3) and then activates the AKT by phosphorylation?
PI3K (phosphatidylinostiol 3-kinase)
What is the phospholipase C pathway activated by?
A GPCR more specifically the alpha protein from the trimeric G protein
Can the different signaling pathways influence each other?
Yes
How do the different signaling pathways influence each other?
Crosstalk
Where is the most common target of signaling?
Nucleus
What are the consequences of the nucleus being targeted?
Transcription
Cell division
What are the consequences of Actin/Tubulin/Filaments being targeted?
Cell structure and motility
What are the consequences of enzymes being targeted?
Initiate metabolic pathways
What are the consequences of receptors being targeted?
Alter signal transduction
What are the consequences of transporters being targeted?
Change intracellular environment
What are the consequences of Ion channels being targeted?
Change membrane potential
What are three important items about epinephrine signaling?
- Affects vascular tone
- Co-administered with local anesthetics
- G-protein and PLC signaling
Which pathway regulates cellular division and metabolic processes, transports glucose into cells, alters blood sugar, enables aerobic respiration?
Insulin signaling
What pathway uses RTK, MAPK, and PI3K signaling?
Insulin signaling
What pathway uses G-protein and PLC signaling?
Epinephrine signaling
What pathway is co-administered with local anesthetics?
Epinephrine signaling
What receptor interacts with epinephrine and activates the GPCR causing stimulus of vasodilation and smooth muscle relaxation?
Beta-adrenergic protein
What receptor interacts with norephinephrine and epinephrine that leads to smooth muscle contraction and vasoconstriction?
Alpha-adrenergic receptor
What type of receptor does insulin initially bind to?
Receptor Tyrosine Kinase
Once insulin is bound to receptor tyrosine kinase what is the next two places it can go?
MAPK pathway PI3K pathway (both via IRS-1)
Why is the Kd important?
It shows the affinity that receptors bind to ligands
