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Cell Biology Chapter 11

Terms in this set (63)

Cells need ___________ ___________ in order to survive, grow, divide, and differentiate
cell signaling
A cell's response to a cell signal depends on the presence of a ___________ and a ___________ ___________
receptor, response pathway
Signals are ___________ molecules that contact a cell and change its behavior; they can either be ___________-___________ or ___________-___________ or ___________
extracellular, membrane-permeable, membrane-impermeable, physical
___________ are found either on the cell surface or inside of the cell and they receive the signal, while ___________ are found either in the cytoplasm or the nucleus and actually cause the change in behavior
receptors, effectors
___________ ___________ are small molecules used to relay and amplify a message
second messengers
___________ occurs when the effects of the receptor activate "signal amplification"
transduction
A ___________ ___________ occurs when signaling proteins and second messengers couple the receptors to the effectors, inciting a cell response
signal cascade
Several different types of cells can have different responses to the same signaling protein because they have different ___________ or ___________
receptors, pathways
In ___________/___________ pathways, each receptor has its own effector
simple/linear
___________ pathways allow for signal ___________ -- two or more signals affect the same effector
convergent, integration
___________ pathways allow for signal ___________ -- one signal affects several effectors
divergent, distribution
___________ pathways allow for ___________ ___________ -- combining signal integration and signal distribution
branched, complex control
Membrane-impermeable signals (most signals are this type) are ___________ molecules, ___________, or ___________ that are soluble in the ___________ ___________
polar, polypeptides, proteins, extracellular fluid
Membrane-permeable signals are either ___________ or _________ that enter ________ cells but only affect ________ cells
lipids, gasses, all, some
Four types of primary action:
1. Enzymes -- protein ___________ and GTP ___________
2. Protein-Binding -- active ___________
3. DNA-Binding -- ___________ factors
4. Ion Channels -- allow _______ flow
kinases, cyclases, g-proteins, transcription, ion
G-Protein Coupled Receptors:
1. The extracellular N-terminus of GPCR binds the signal molecule -- ___________
2. A ___________ change is made
3. The cytosolic loop of GPCR binds a ___________ ___________, activating it and causing it to active the targets
ligand, conformational, heterotrimeric g-protein
GPCR is only active as long as ___________ is bound
ligand
Active GPCR may activate several ___________ ___________, resulting in signal amplification; this is an example of a ___________ pathway
trimeric g-proteins, divergent
Receptor protein (tyrosine) kinases ___________ when bound to ligand
dimerize
Phosphates are added to ___________ sidechains on proteins
tyrosine
Receptor protein tyrosine kinases activate kinases on the ___________ domain of proteins
cytosolic
___________ ___________ occurs when the terminal phosphate of _______ is transferred to the sidechain of a protein--changing its ___________
protein phosphorylation, ATP, conformation
Most kinases act on ___________ and ___________
serine, threonine
Protein phosphorylation is reversed by the action of ___________
phosphatases
Receptor protein serine/threonine kinases primarily act to ___________ target proteins--changing their ___________ and ___________
phosphorylate, conformation, activity
A ___________ is a molecule to which a protein binds
ligand
Ligand-gated ion channels are primarily used in signal transmission from ___________ to ___________, ___________, or ___________ -- for example, nicotinic receptors bind acetylcholine
neurons, neurons, muscles, glands
Transmembrane scaffolds are triggered by ___________ factors and are associated with the ___________ and ___________
physical, cytoskeleton, integrin
___________ proteins are adapters that hold the transmembrane scaffold together, coupling the ___________ to ___________
scaffold, cytoskeleton, integrin
In the transmembrane scaffold, ___________ proteins add ___________ to phosphatidylinositol (PI) via ___________ kinases and ___________ kinases
signaling, phosphates, protein, lipid
Guanylyl cyclase is active only as long as a ___________ is bound
ligand
Guanylyl cyclase converts GTP to ___________ ______ -- a form of ______ with a phosphate bound to the ___' carbon and the ___' carbon
cyclic GMP, GMP, 3, 5
Cyclic GMP is a ___________ ___________, that functions in signal amplification
second messenger
Nuclear receptors are ___________-like receptors found in the ___________; they function in increasing ___________ when ___________ is bound
lipid, cytosol, transcription, ligase
When a "default" signal (no signal) is sent to a cell, the cell undergoes ___________
apoptosis
How do cancer cell's cell surface receptors differ from typical cell surface receptors?
Cancer cells don't require cells signals to grow, divide, or DIE. It is an independent, non responsive cell. Therefore, its receptors are either nonexistent, inactive, out of place, non responsive, etc.
Steps in G-Protein hydrolysis:
1. ________-bound g-protein is ___________ (active/inactive)
2. ________ swaps GDP for GTP
3. ________-bound g-protein is ___________ (active/inactive)
4. ________ kicks off one ___________
GDP, inactive, GEF, GTP, active, GAP, phosphate
GPCR is a ___________ of ___ different polypeptides; ___________ and ___________ are anchored membrane proteins; ___________ acts as the g-protein, binding GEF in order to bind GTP and become active
trimer, 3, alpha, gamma, alpha
G-alpha and G-beta-G-gamma are only re-bound if ____ ___________ occurs
GTP hydrolysis
___________ ___________ is a signaling protein stimulated by G-alpha-GTP
Adenylyl cyclase
Adenylyl cyclase converts molecules of _____ to ___________ _____ by releasing a pyrophosphate; it also often functions in signal ___________
ATP, cyclic AMP, amplification
Cyclic AMP is hydrolyzed by ___________ ___________, making AMP
cAMP phosphodiesterase
Adenylyl cyclase is regulated by more than one ___________ ___________ -- ________ stimulates it, while ________ inhibits it
trimeric g-protein, GAS, GAI
GAS fights to make stimulate adenylyl cyclase, while GAI fights to inhibit adenylyl cyclase; this is a classic example of ___________ ___________
signal integration
Protein Kinase A (PKA) is stimulated by _________ and functions in signal amplification (making it a SECOND MESSENGER) via ___________ ___________ when it releases free active ___________ subunits
cAMP, kinase cascade, catalytic
Lipid kinases add ___________ to lipids in _____, forming _____
phosphates, PI, PIP2
Phospholipase C acts on PIP2 to generate _____
IP3
IP3 is a ___________ ___________ that is membrane-___________ (permeable/impermeable)
soluble signal, permeable
List the four second messengers
cAMP, cGMP, IP3, calcium ions
Ca++ binds ___________, causing a shape change that allows the molecule to bind various targets in the cell
calmodulin
Nuclear effect (pathway) of cAMP:
1. ___________ ___________ +
2. ________ =
3. ________ -->
4. ________ -->
5. ________ +
6. ________
--> together, steps 5 and 6 activate ___________ ___________ in the nucleus
adenylyl cyclase, ATP, cAMP, PKA, CREB, CBP, transcription factors
Cytoplasmic effect (pathway) of cAMP:
1. Glucose mobilization from ___________ (via _____)
2. ________
3. ________ (inactive) --> inactivates ___________ ___________
4. ___________ ___________ ___________ (active)
5. ___________ ___________ (active)
6. ___________
--> overall resulting in a kinase cascade
glycogen, GAS, cAMP, PKA, glycogen synthase, glycogen phosphorylase kinase, glycogen phosphorylase, glucose-1-p
PKA ___________ glycogen synthase, ___________ (activating/deactivating) it
phosphorylates, deactivating
Phospholipase C is activated by _____ and _____
DAG, Ca++
In order to activate phospholipase C, G-alpha-GTP hydrolyzes PIP2, forming _____ (which diffuses into the _____, opening a _____ channel) and _____
IP3, ER, Ca++, DAG
Protein Kinase Receptor Pathways grow the cell via ___________ ___________
growth factors
Protein Kinase Receptor Pathway:
1. A Tyr-P receptor is recognized by the "_____" ___________
2. The Tyr-P receptor docks an ___________ ___________
3. This binds a ___________ ___________ called "_____"
4. This binds and activates a ___________
5. This induces a ___________ ___________, resulting in amplification of ___________ ___________
SH2 domain, adaptor protein, monomeric g-protein, ras, kinase, kinase cascade, transcription factors
___________ is a molecule that promotes cell division and growth
mitogen
MAP Kinase Pathway:
1. "_____" binds GTP
2. Phosphorylation to _____ _____
3. Phosphorylation to _____ _____
4. Phosphorylation to _____ _____
5. ___________ ___________ are formed
6. This results in ___________ ___________ (signal ___________ and ___________)
ras, MAP KKK, MAP KK, MAP K, specific kinases, cell proliferation, amplification, distribution
PI 3-Kinase is stimulated by a ___________ ___________ and is active only as long as it is bound to _____
lipid kinase, RTK
Phosphoinositol phospholipids (PIPLs) are generated by ____ ___-__________, and they are used as ___________ ___________ for kinases to relay ___________ ___________
PI 3-Kinases, docking sites, cell signals
MORE THAN ONE ___________ ___________-_____ phosphorylates Akt, activating it
Protein kinase-1
Akt stops ___________ ___________ and promotes ___________ ___________; it also activates ___________ (a ser/thr protein kinase) which reduces ___________ ___________ and promotes ___________ ___________
cell death, cell growth, Tor, protein degradation, protein synthesis
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