Lecture notes
Cell Cycle
- Module
- CANCER BIOLOGY LECTURE NOTES
- Institution
- University Of East Anglia
4 Key Cell Cycle Checkpoint
[Show more]
Seller
Follow
Content preview
CL6: CELL CYCLE [04/10/2022]I. KEY CONTROL PROTEINS: cyclin dependent kinase (CDK or CDC) + cyclins
Cyclins bind CDKs and affect the latter’s abilities to phosphorylate, serine and
threonine residues of their substrate.
CDKs – 40% homology with one another
Cyclins – 100 amino acids residue long domain
II. FOUR KEY CELL CYCLE CHECKPOINT
III. CYCLIN DEPENDENT KINASE
Proline-directed serine/threonine kinases
Activity regulated by:
- Protein-protein interactions
- Regulatory (+ and -) phosphorylation
- Results in a conformational change (opening if the substrate cleft)
IV. CYCLINS
Large and diverse family 50-90 kDa (29+ genes)
, ‘Cyclin box’ ~100 amino acids – interaction with kinase partner
Transcriptional and post-transcriptional controls on cyclin levels:
- Transcription: cell cycle specific transcription factors
activity of cyclin/CDK complexes themselves
- Protein Abundance: rapid degradation (ubiquitylation / proteasome)
- Protein Location
D Type Cyclins (D1, D2, D3)
- Expression can be induced by
growth factors (mitogens) =
integration of multiple signalling
pathways through control of CDK4
and CDK6 activation.
- G0 progression to G1
- Oncogene activation drives cyclin D
expression
Different types of cyclins confer
distinctive substrate specificity to a
catalytic CDK subunit of complex (Cyclin
A binding to CDK2 results in a 400,000-
fold increase in activity)
Programmed phosphorylation of
specific substrates drives cell through
different phases of cell cycle
Cyclin production and degradation
ensures cell cycle can only occur in one
direction.
V. CDK
CDK proteins are inactive unless bound to cyclin partner. Non-cyclin partners can
also activate CDKs
Cyclin-CDK complex subject to further negative and positive regulation via
phosphorylation
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 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 biologicalscientistgal. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for £7.16. You're not tied to anything after your purchase.
Can Stuvia be trusted?
4.6 stars on Google & Trustpilot (+1000 reviews)
53022 documents were sold in the last 30 days
Founded in 2010, the go-to place to buy revision notes and other study material for 14 years now