Signal Transduction Flashcards
what are examples of intercellular signals?
endocrine – hormones, insulin, glugagon, epi, steriods, peptide
Autocrine - eicosanoids
Paracrine - NTs, GFs, NO, neuron signaling, contact signaling
what are the 4 basic types of receptor-mediated signal transduction – extracellular signals producing intracellular signals
- steroid receptor
- Gated-ion channel
- Receptor enzyme (catalytic receptor)
- G-protein coupled receptor (GPCR)
what are examples of steroid receptor molecules?
testosterone, estrogen, cortisol,
Vit. D and retinoic acid (vit. A)
thyroid hormone
aldosterone
what do steroid receptor molecules do?
penetrate cellmembrane and bind to intracellular receptors
hydrophobic/lipophilic
induce up regulating gene expression at the level of DNA transcription and gene enhancment
which is the slowest signal transaction?
steroid receptor
what are zinc finger motifs?
binds to specific sequence of bases in major groove of DNA - has alpha helix, beta sheet and cystein, histidine and zinc idk?
what are examples of gated ion channel molecules?
nicotinic Ach receptors of muscle or nerve
gamma aminobutyric acid (GABA) and glycine receptors in CNS
what is an example of receptor enzymes molecules?
insulin receptor = tyrosine kinase
what are the intracellular effectors of receptor enzyme ?
IRS (insulin receptor substrates 1-4)
adaptors
enzyme effectors
what are the cellular responses of Insulin receptor (receptor enzymes)?
increased glucose uptake
regulation of transcription of certain proteins
activation of enzymes
how are the enzymes activated in insulin receptor tryosine kinase?
covalent modification - phos/ dephos,
upregulation(increase synthesis of enzymes)
what are beta subunits?
tyrosine kinases
what happens after the tyrosine kinase domains of the insulin receptor are activated by insulin?
interchain autophosphorylations - phosphates are added
what are examples of GPCR and intracellular second messengers?
adenylate cyclase system (cAMP)
calcium/phosphotidylinositol system (IP3, DAG, and Ca2+)
protein kinase A
what are examples of intracellular second messengers?
cAMP
IP3, DAG, ca2+
cGMP
NO
