Signaling Molecules and Mechanisms Flashcards
What is the basic mechanism of signaling during mating in yeast?
The mating Signaling pathway is regulated by signals from yeast alpha and A cells
The alpha yeast cells contain “A” receptors and secrete alpha peptide mating factor
The A yeast cells contain alpha receptors and secrete “A” peptide mating factor.
Once the factors bind to the receptors of the opposite yeast cells and stop proliferating and prepare to mate.
Why studies of these yeast signaling pathways were important to later studies of cancer in mammals?
Hint: Look at this roadmap
Genes that were mutated in human cancer were the same type of genes in the yeast roadmap.
Researchers used similar roadmaps in yeast to rapidly find the mutated genes in human cancer, instead of searching 20,000 human genes.
Increase the process in cancer research
Choose the best option
(Between cells signaling/Within cells signaling / Between Protein Molecules signaling )
_______________ use systemic mediators such as hormones. Also use local mediators such as tissue hormones, cytokines, lipid mediators, neurotransmitters, and nitrogen monoxide. Use cell surface proteins such as cell adhesion molecules. This is also known as Inter-cellular signaling.
Between Cell Signaling
Choose the best option
(Between cells signaling/Within cells signaling / Between Protein Molecules signaling )
______________ use second messengers such as cyclic nucleotides, diglycerol, inositol phosphates, phosphoinostidie, Ca2+ interaction domains of proteins. Also known as Intra-cellular signaling.
Within cells siganling
Choose the best option
(Between cells signaling/Within cells signaling / Between Protein Molecules signaling )
______________ does conformation changes.
Between protein molecules
True or False, if False, rewrite the statement so it will be true.
___ Intra-cellular signaling is mediated by proteins.
_____ Protein is primarily through rapid and reversible changes in the activity of the existing protein.
_____ The changes in activity are primarily mediated by allosteric conformational changes
____ Protein can functional as discriminators
____ Binding event at one site on a protein triggers an initial local conformation change that leads to an altered structure, function at a different (distant) site on the same proteins.
T
T
T
F, Protein can functional as transducers
T
Why do we compare protein to polarized neurons for the inputs and outputs signals?
For neurons
The input signals, the initial local change in membrane potential, occurs at the dendrites. The output signal occurs at the axon and synapse (distant) site, a subsequent local change in membrane potential to generate output.
For proteins
The input signal happens at the regulator domain, extracellular domain. The signal is allosteric coupling to the catalytic domain, intracellular domain, and create the output signal.
Why is allosteric conformation changes are advantageous in the protein of intracellular signaling?
Allows control of the protein, from inactive form, very rapidly and reversible
What are the major mechanisms by which the activity of proteins is regulated?
There are five
Ligand binding, non-covalent
Covalent Modification, (phosphorylation)
Binding of An Activating Protein
Unmasking and inhibitors
Translocation/Trafficking
What are some examples of non-covalent and covalent interactions that mediated the allosteric changes in protein structure?
Non-covalent interaction is ligand regulation
like cAMP binding making the protein active and dilution of cAMP will inactive the proteins
Covalent interaction is phosphorylation regulation
Use an enzyme (kinase) to activate the inactive protein and use a phosphatase to inactive the protein
Looking at the signaling Modes
Which one describes the simple situation?
A
Looking at the signaling Modes
Which one describes the Not situation?
B
Looking at the signaling Modes
Which one describes the AND situation?
C
