BIO 1140 Lecture Notes - Lecture 12: Lipid-Anchored Protein, Gtpase, Reuptake

18 views3 pages

For unlimited access to Class Notes, a Class+ subscription is required.

Thu, February 25 - Lecture 12 Signal transduction part 2
Slide 3
cells don't send transcription factors, but some messengers CAN act as transcription messengers
(i.e: thyroid hormones, steroids)
Slide 5
Intracellular receptors can be in the cytosol or in the nucleus. Depending on how far the target
cell is, it can use different paths (last lecture). Once it binds to the receptor, it forms a complex
(which acts as the transcription actor).
Slide 5
How does it know which genes it can actually turn on or off? Response elements - patterns in the
genes that it recognizes. As long as its bound to its target, mRNA can be released etc.
Slide 6
Cortisol is distributed by the endocrine pathway, is going to reach cells that have cortisol
receptors. The receptor is inactive, waiting for its messenger to arrive and bind to a specific
binding area (lock & key), lets go of chaperone protein, cell is now active (transcription factor).
Goes to nucleus, find ones that have sequences/genes that recognize transcription factor for
cortisol. In response, turns on or off transcription. Same pattern for all lipophilic messengers.
Slide 7
Transmembrane receptors. #1: Ligand gated ion channels. Must be open or closed by binding
messengers. Ligand will always bind on extracellular side of membrane, hydrophilic. Bind
messenger, conformation changes, allows the passage of ions. As long as the messenger is bound
to the channel, it will stay in that conformation and allow the passage of ions. Some are specific
(will only let one ion through), some will let all kinds of ions through.
Slide 7
When the channels are open, it changes the membrane potential. Difference in charge between
both sides of the membrane. This difference in charge creates a gradient & potential energy
(membrane potential) that is measurable [in volts]. When this concentration changes enough,
action potential is formed.
Slide 8
When you have enough of this energy, it can cause other channels to open as well.
Slide 9
Acetylcholine: neurotransmitter released in a synapse, (postsynaptic protein receives it).
Inotropic receptors.
Slide 10
ACh has 5 subunits, when ligand binds to it the conformation changes, letting in Na and CA in,
while releasing some K+.
find more resources at
find more resources at
Unlock document

This preview shows page 1 of the document.
Unlock all 3 pages and 3 million more documents.

Already have an account? Log in

Get access

$10 USD/m
Billed $120 USD annually
Homework Help
Class Notes
Textbook Notes
40 Verified Answers
Study Guides
1 Booster Class
$8 USD/m
Billed $96 USD annually
Homework Help
Class Notes
Textbook Notes
30 Verified Answers
Study Guides
1 Booster Class