Cell cycle II - Cyclin-dependent kinases (Cdk's) and cyclins in the mammalina cell cycle

10 important questions on Cell cycle II - Cyclin-dependent kinases (Cdk's) and cyclins in the mammalina cell cycle

Which type of cylcins contain a destruction box thatr is recognized by the APC ubiquitin ligase?

Type B cyclins

Name 2 characteristics of cultured G0 cells in the absence of growth factors

1. G0 cells express neither cyclins nor CDKs
2. G0 cells do not progress through the cell cycle and relicate

By which factors is the mammalian cell cylce induced?

Growth factors
  • Higher grades + faster learning
  • Never study anything twice
  • 100% sure, 100% understanding
Discover Study Smart

Which two classes of genes are expressed that drive cells back into the cell cylce?

1. Early-response genes
2. Delayed-response genes

Name 3 characteristics of early-response genes

1. Transcription of early-repsonse genes is induced after addition of growth factors
2. Inducton of transcription not blocked by inhibitors of protein synthesis
3. Encode transcription factors that stimulate transcription of delayed-response genes

Name 2 characteristics of delayed-response factors

1. Induction of transcription is blocked by inhibitors of protein synthesis
2. Code for additional transcription factors such as E2Fs, D type cyclins, cyclin E, Cdk2, Cdk4 and Cdk6

On what does passage of the restriction point depend?

Activation of the E2F delayed-response transcritpion factors which induce the expression of Cdk2, S-phase pecific enzymes and cylcins A and E

What are the 5 steps of regulation of E2f transcription factors?

1. E2F activation is inhibited by binding to retinoblastoma tumor suppressor (Rb)
2. Rb converts E2Fs from trancriptional activators to repressors by recruitng histone deacetylase complexes to DNA-bound E2F
3. Cyclin D-Cdk4/6 will phosphorylate Rb
4. Rb releases E2F
5. E2F can recruit histone acetyltransferases to activate target genes

In what 3 ways can mammalian Cdks be regulated?

1. Cyclin availability, inactive catalytic subunit Cdk needs positive regulatory subunit cyclin
2. Phosphorylation and localization of Cdks and cyclins can control Cdk activities
3. Binding of inhibitory proteins

What are the two classes of cyclin-kinase inhibitors of mammals?

1. CIP (CDK inhibitory protein) family
2. INK4 (inhibitors of kinase 4) family

The question on the page originate from the summary of the following study material:

  • A unique study and practice tool
  • Never study anything twice again
  • Get the grades you hope for
  • 100% sure, 100% understanding
Remember faster, study better. Scientifically proven.
Trustpilot Logo