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15 Cards in this Set
- Front
- Back
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Precursors of Ach synthesis
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choline
acetyl CoA |
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What is the enzyme for reaction
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choline acetyl transferase
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What transports Ach to vesicle
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Ach vesicular transporter
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How do you regulate production of Ach
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1. negative feedback--> Ach buildup reverses ChAT by mass action
2.availability of choline - with increased activity, get more fusion and thus more HACU on plasma membrane, uses Na gradient to bring in choline |
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How does Ach termination work
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ACHase activity in synapse breaks it down - choline is reuptaken
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Name unique identifiers of Ach
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-high affinity choline uptake transporter(HACU)
-ChAT -Ach vesicular transporter -presense of Achase in ECM (less good) - |
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How is dopamine formed
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tyrosine is transformed to L-DOPA by tyrosine hydroxylase
L-DOPA is converted to dopamine by AAAD |
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What transporter moves dopamine into vesicle
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VMAT
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How is dopamine converted to norepinephrine? where?
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by enzyme dopamine beta hydroxylase,in the vesicle
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What transports NE out of vesicle
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VMAT
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How is NE transformed to epi
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by enzyme PNMT
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What transports it to vesicle
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VMAT
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How is catecholamines synthesis regulated?
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-negative feedback of tyrosine hydroxylase - DA, EPI, NE competitively inhibit TH by competing with BH4 - its cofactor
-phosphorylation of tyrosine hydroxylase by CAMKII - 20 fold increase in BH4 affinity, occurs after long train of AP's--> increased Ca-->activate CAMKII --> phosphorylating tyrosine hydroxylase |
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How is catecholamines terminated
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-monoamine oxidase (MAO) - synaptic enzyme that degrades DA, NE, EPI
-catechol-o-methyl transferase (CoMT) also degrades DA, NE, EPI in synapse -reuptake pump-separate types exist for DA and NE/EPI which are ATP dependent |
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What is unique identifier of DA
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-presense of tyrosine hydroxylase in absense of dopamine beta hydroxylase and PNMT
-DA reuptaker (DAT) |
