BSI Lecture 17-18 Cell Signaling Examples Flashcards
cAMP most important target is ________ __
Phosphokinase A
PKA has many important targets affected by __________.
Phosphorylation
Cells are subject to many different messengers from ___ to ____ and this is superimposed on the changing status of the cell itself.
second; second
What turns ATP in to cAMP
Adenylyl Cyclase
What turns cAMP into AMP?
Phosphodiesterases
What does PKA stand for?
Phosphokinase A
PKA is activated by _______
cAMP
When PKA phosphorates a target protein, they phosphoralate specific _____ ______ ______.
Amino acid residues
Does PKA turn on or off target proteins?
They can turn them on or off
The effects of PKA are reversed by _______
Phosphotase
What can reverse the effects of PKA?
Phosphotases
What does PKA phosphorylate on the target proteins?
Specific amino acid residues
T or F? PKA can only turn things on?
False, it can turn them on or off
Name the targets PKA can affect.
1) Active transport
2) Channel protein
3) ER (protein synthesis, Ca2+ transport)
4) Can act as transcription factor
5) Enzyme, lipid breakdown
6) Enzyme, glycogen breakdown
7) microtubules
When cAMP activates PKA, then PKA activates an inactive phophorylase kinase, what is this an example of?
Kinase cascade
Can PKA enter the nucleus freely?
No, it’s too large and needs to be transported in
What are PLs?
Phospholipases
PLs produces different ______ _______ to mediate their effects.
secondary messengers
Phosphatidylinositol biphosphate (PIP2) when cleaved by PLC and disassociates into ____ _____
IP3 (Inositol triphosphate) and DAG (Diacylglycerol)
T or F? DAG is hydrophilic.
False, hydrophobic
When PIP2 is cleaved, what 2nd messenger goes to the ER and opens up a Ca2+ channel?
IP3 (Inositol triphosphate)
What needs to happen before PKC is fully activated?
Ca2+ needs to bind with it along with DAG
PLA2 will release _______ _____
Arachidonic acid
If you take an NSAID, what does it block to prevent you from feeling pain.
Cyclooxygenase (COX1 and COX2)
Prostaglandins (PGs) and thromboxanes(TXs) have functions that include _____ and _____.
Inflammation; fever
What do Leukotrienes affect?
Immune cell function (acting on leukocytes)
“De novo” synthesis of Sphinganine, Sphigosine, and ceramide are initiated by what enzyme?
Serine palmitoyltransferase (SPT)
Serine palmitoyltransferase (SPT) can be blocked by what?
SPT Inhibitor
Name the types of sphingolipids.
Sphinganine, Sphingosine, Ceramide, Sphingosine 1-P
______ are mycotoxins that disrupts sphingolipid messenger functions.
Fumonisins
Sphinganine, Sphingosine, Ceramide can either be made by ‘De novo” or by recycling of _________ ________ in membranes.
Complex sphingolipids
If you tip the scale on the levels of sphingolipids towards Sphingosine 1-P, what will occur?
Anti-apoptotic, proliferation, mitogenesis, inflammation
could lead to cancer
If you tip the scale on the levels of sphingolipids towards ceramide, what will will occur?
Apoptosis, cell cycle arrest
Omega-3 fatty acids are ____ __________.
Anti-inflammatory
Omega-6 fatty acids are ____ __________.
Pro-inflammatory
We do not make omega-3’s, if we are missing them in our diet, what are they replaced with and why is it bad.
They are replaced with Omega-6 and they are pro-inflammatory
Ca2+ is effective on its own as 2ndary messenger, but sometimes it needs to bind with __________.
Calmodulin
What does activated MAPkkk do?
Initiate a kinase cascade by phosphorylating MAPkk, which then phosphorylates MAPk, which phosphorylates target proteins that affect important processess like transcription.
Inappropriate signaling in LMW G-protein/kinase cascade pathways can result in ________as they are so central in controlling cell growth.
cancer
Cell will undergo ______ if it is not told to survive.
Apoptosis
PI3-kinase (phosphoinositide 3-kinase) activates Akts (serine/threonine-protein kinase family) by producing PIP3 from PIP2 (DAG/IP3 pathway) by phosphorylation. PIP3 activates protein kinase 1 in turn activates Akts, which releases ______________
Bcl-2
During contact-dependent chemical messaging, the delta signal protein reaches the delta receptor of another cell, what happens to the Notch?
The tail is cleaved and migrates to the nucleus. Without this “growth limiting” system, cancer may result
