Summary
Summary BIO 2001 Lectures & Tutorial Notes
- Course
- Institution
- Book
Answers to the learning goals of every task of the course (as of 2021) and summaries of all the lectures.
[Show more]
Connected book
Book Title:
Author(s):
- Edition:
- ISBN:
- Edition:
More summaries for
-
molecular biology of the cell testbank of chapter 15 cell signaling and answers
-
The lipid bilayer
-
Apoptosis
Seller
Follow
aliciahobdell
Content preview
Alicia HobdellMSP’23
Task 10: The Dual Role of Insulin
Insulin Receptor 3. Akt is phosphorylated by mTOR kinase on
a serine then by PDK1on a threonine,
Receptor tyrosine kinase (= enzyme-coupled
causing its activation.
receptor); insulin receptor is a dimer that
4. Activated Akt dissociates from the plasma
comprises two α-chains and two β-chains.
membrane and phosphorylates target
● Binding of insulin to the RTK stimulates
proteins (e.g., Bad)
carbohydrate utilization and protein
Survival
synthesis
● Binding of insulin-like growth factor (IGF1)
to the RTK stimulates cell growth and
survival in many cell types
Binding of a ligand to
the α-subunit of the
RTK →
conformational Bad holds apoptosis-inhibitory proteins (Bcl2 in an
change → brings the inactive state
β-chains closer 1. Bad phosphorylation releases the
together → inhibitory proteins, blocking apoptosis and
phosphorylate each promoting cell survival.
other on tyrosines. Glucose Uptake
Insulin Signaling Pathways
The tyrosine-kinase receptor system allows the cell
to trigger several signal transduction pathways and
cellular responses at once.
PI-3-Kinase–Akt Signaling Pathway
1. AKT catalyzes the phosphorylation of
AS160, stimulating the translocation of
1. Binding of IGFs or insulin to specific RTKs GLUT4 (= glucose transporter) from the
recruits and activates PI-3-kinase GLUT4 storage vesicles (GSV) in the
2. The PI-3-kinase phosphorylates PI(4,5)P2 cytoplasm to the cell membrane.
to PI(3,4,5)P3, which serves as a docking 2. GLUT4 accumulation in the plasma
site for Akt (= protein kinase B, PKB) and membrane promotes glucose uptake by
phosphoinositide-dependent protein the liver and adipose tissue → decrease in
kinase 1 (PDK1) via their PH domains, blood glucose concentration
bringing them into proximity at the plasma
membrane
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller aliciahobdell. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $54.86. You're not tied to anything after your purchase.
Can Stuvia be trusted?
4.6 stars on Google & Trustpilot (+1000 reviews)
78252 documents were sold in the last 30 days
Founded in 2010, the go-to place to buy study notes for 14 years now