Signals transduction Flashcards
The process by which a cell detects and responds to signals in its environment is called
Cell communication
A type of cell-cell communication where signals are releasd into the circulatory system to target cells
Endocrine signaling
A type of cell-to-cell communication where a cell produces a signal to induce changes in nearby cells.
Paracrine signaling
In this type of signaling, the cell sends signals to itself, releasing a ligand to bind to receptors on its surface
Autocrine signaling
Which cell communication involves direct contact between cells
Juxtacrine
What photopigment is responsible for detecting light in the case of the circadian clock
Melanopsin
A ligand that binds to a receptor and triggers a response is known as
An agonist
Which ligand binds to a receptor but blocks the activation of the receptor?
An antagonist
A change in the conformation of a receptor caused by the binding of a signaling molecule with the receptor is called
Receptor activation
Which secondary messenger opens calcium channels to transport stored calcium ions?
Inositol triphosphate (IP3)
What are the four typres of receptor Families
Ligand-gated ion channels
G protein coupled receptor
Enzymatic receptors(tyrosine kinase)
Nuclear hormone receptor(gene expression regulating receptor)
What causes Cystic Fibrosis
Mutation in the CFTR gene, Whichb is a ligand gated chanel chanel
What causes congenital Lymphatic Displasia
Defiency in PIEZO1 a mechanosensitive ion channel protein
What causes generalized epilepsy with febrile seizures plus
Voltage gated ion channel disease
The process by which a cell becomes less responsive to a ligand is called
Desensitization
Genetic and autoimmune disorders of ion channels are known as
Channelopathies
What kind of ion channel disease is generalized epilepsy with febrile seizures plus (GEFS+)?
Voltage gated ion channels are disease
What kind of ion channel disease is cystic fibrosis?
Ligand gated ion channel disease is cystic
Cystic fibrosis is caused by mutation in what gene?
CFTR gene
What kind of channel disease is congenital lymphatic dysplasia?
Mechanosensitive ion channel
Congenital lymphatic dysplasia is caused by a deficiency in what protein?
PIEZO1
What are the three subunits of G-protein couples receptors?
Alpha
Beta
Gamma
What are the main G-protein Targets
Adenylyl Cyclase
Ion Channels
Mitogen-Activated Protein Kinases
Phospholipase C
RhoA/Rho Kinase
What are the other names for a g-protein coupled receptor
7-transmembrane receptors
Heptahelical receptor
Serpentine receptors
Metabotropic receptors
What percentage of drugs target G protein coupled diseases
40%
Give Examples of GPCR
Beta-adrenergic receptor
Prostaglandin Receptors
Rhodopsin
Which g protein alpha subunit is responsible for activates adenylyl cyclase
Gs alpha protein
Protein kinase A is also known as
cAMP-dependent enzyme
Why is Protein kinase A also known as cAMP-dependent enzyme?
This is because it gets activated only when cAMP is present
Which molecules inhibit cAMP pathway?
cAMP phosphodiesterase
Gai protein(A G protein)
Which molecules activate cAMP pathway
Epinephrine
Caffeine
Theophylline
Which G protein inhibits Adenylyl Cyclase
Gi protein
How does caffeine activate cAMP pathway
Caffeine inhibits cAMP phosphodiesterase
What are the process in the Phosphotidylinositol(PIP2) pathway
Phospholipase C catalyzes the hydrolysis of Pip2 to IP3 and DAG
IP3 acts a secondoray messenger and binds to THe IP3 receptoron mitochondria and ER to open Ca2+
What is the function of DAG
It activates protein kinase C
What pathway does the release of Ca2+ activate
Calmodulin(CaM) Kinase pathway
Which g proteins activate Rho Kinase
G12/G13 G proteins
How do the G12/G13 proteins regulate cell processes
The free g-protein alpha subunit interacts with Guanosine nucleotide exchange factor(GEF) that facilitates the GDP-GTP exchange on the gtpase Rho
Rho-GDP activated to form Rho-GTP by the exchange goes on to activate Rho kinase
An inhibitor of Rho-Kinase
Fasudil
What inhibits Rho-GDP from activation
GDI (Rho guanine nucleotide dissociation inhibitor)
What inactivates Rho-GTP
GAP - GTPase activating protein
What are the first and second steps in the insulin Pathway
Insulin Binds to the receptor tyrosine kinase
This binding phosphorilates the rece[tor which the phosphorylates and binds IRS-1
What are the third and fourth steps in the insulin pathway
PI 3Kinase binds to THE IRS-1 bound to the receptor
PI 3 Kinase then phosphorylates PIP 2 to form PIP3
What are the fifth and sixth steps in the insulin pathway
PDK-1 then binds to PIP3 and activates AKT
AKT causes a cascade of events(conerts RAB GDP to GTP) which causes GLUT4 glucose transporters to move to the cell membrane taking in more glucose form blood reducing blood glucose levels
What are tyrosine kinases?
Kinase enzymes that specifically phosphorylate tyrosine amino acids
A cell surface receptor that also has tyrosine kinase activity is called
Receptor Tyrosine Kinase ( RTKs)
What is the other name for the MAPK/ERK pathway
Ras-Raf-MEK-ERK pathway
What is the effect of the MAPK/ERK pathway
The Ras-Raf-MEK-ERK pathway leads to cell growth and proliferation
What does a mutated Ras protein in the MAPK/ERK pathway causes
It causes repeated proliferation hence forming tumour cells and cancer cells
This is because GAP isnt able to deactivate the Ras protein
Raf protein is the GTPase in the MAPK/ERK pathway. True or False
False, Ras is the GTPase in the MAPK/ERK pathway
Which protein activates Ras
SOS
The three components of the JAK-STAT
A receptor
Janus kinase family proteins
Signal transducer and Activator of Transcription (STAT)
What is the main function of non receptor tyrosine KInase(nRTK)
The main function of nRTKs is their involvement insignal transductionin activatedT-andB-cellsin the immune system.
What receptors are required for nRTKS signaling in T lymphocytes
CD4 and CD8
What are the diseases caused by malfunction in JAK/STAT
Rheumatoid Arthritis
Inflamnatory Bowel disease- Crohns disease and Ulcerative colitis)
Myeloproliferative neoplasms
Multiple Myeloma
What is myeloproliferative neoplasms?
Blood cancers that occur when the body makes too many white or red blood cells or platelets.
What is multiple myeloma?
It is a cancer that forms in a plasma cell causing the plasma cell to produce harmful antibodies that cause complications in the body
What downstream targets of Rho kinase are involved in cytoskeletal dynamics?
MLC (Myosin Light Chain), LIM Kinases, ERMs (Ezrin, Radixin, Moesin), Adducin
What is the role of MLC in the Rho/ROCK pathway?
Stress fiber assembly and cell contraction
How does ROCK regulate nitric oxide production?
By activating eNOS (Endothelial Nitric Oxide Synthase)
Which downstream target of Rho kinase is involved in actin-network assembly?
Adducin
What is the function of LIM Kinases in the Rho/ROCK pathway?
Actin-filament stabilization
What is the role of ERM proteins in the Rho/ROCK pathway?
Actin-membrane linkage
Which downstream target of Rho kinase regulates growth cone collapse?
CRMP2 (Collapsin Response Mediator Protein 2)
Which downstream target of Rho kinase is involved in cardiomyocyte contraction?
Troponin T
How does ROCK affect microtubule stabilization?
By acting on Tau protein
What is the role of MLCP in the Rho/ROCK pathway?
Regulates contraction by dephosphorylating MLC
Give examples of intracellular receptors
Nuclear receptors
IP3 receptors found on the endoplasmic reticulum
Give examples of hormones that use intracelllular receptors
Thyroid and steroid hormones
Where are the two main places integrin signaling exist
Circulating blood vessels
Non-circulating blood vessels
What is the main difference between integrins of circulating cells and non-circulating cells
Integrins in circulating cells are usually inactive while integrins in non-circulating cells are active
what type of receptors play a role in identifying Pathogen-associated molecular patterns (PAMPS)
Toll Gate Receptors
What are pathogen-associated molecular patterns(PAMPs)
Theyre molecules broadly shared by pathogens but distinguishable by the host
In relation to the function of Toll Gate receptors
what main general function in the body would they play a key role in
THe immune function of the body
