Cdk-cyclin complex and its regulators in the cell cycle and cancer

Investigate Cdk-cyclin and its associating protein targets in the cell cycle and cancer with highly cited reagents.

Cell division and apoptosis are key aspects of cancer biology. Cdk (cyclin-dependent kinase) associates with cyclins to form Cdk-cyclin complexes which play a crucial role in cell cycle progression. 
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The Cdk-cyclin complexes regulate a series of events that lead cells from a resting state (G0), growth phase (G1), through DNA replication (S), and finally to cell division (M). Abnormalities in cell cycle control that occur in any of the phases leads to cell cycle arrest and might be associated with cancer¹. 

​​Contents

• p21
• MDM2
• Cdk2 (CDKN2, p33)
• Cyclin B1
• Cyclin E1
• Cyclin A1
• Cdc25c
• Cdc6
• Cdk4/6 and cyclin D1/D2
• Retinoblastoma protein (Rb)

p21

​​p21 directly binds to Cdk-cyclin complexes maintaining Cdk in an inactive state². Inactive Cdk cannot phosphorylate downstream targets thereby leading to cell cycle arrest³.

Modulating p21 and its associated Cdk target proteins can cause DNA damage, replication stress, and DNA accumulation and contribute to cancer development. Studying DNA changes during cell cycle arrest will help better characterize cell cycle progression and the effect of target modulation in cancer.

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​​​Click here for the full list of p21 antibodies

MDM2

A negative regulator of p21, MDM2 inhibition elevates p21 while its overexpression has the opposite effect. MDM2 binds p21 and directs it to proteasome-mediated degradation⁴.

Click here for the full list of MDM2 antibodies

Cdk2 (CDKN2, p33)

Cdk 2 is associated with tumor proliferation in multiple cancer types. Binding of p21 to Cdk2-cyclin E complex arrests cells at the G1/S checkpoint. Cdk2 inhibition by p21 is therefore crucial for DNA damage repair⁵.

Type	Reagent name	Description	AbID
Antibody	Anti-Cdk2 antibody​	Type: Rabbit monoclonal antibody Reactivity: Hu, Mo, Rt Applications: ICC/IF, IP, WB, Flow Cyt, IHC-P	ab32147
	Anti-CDK2 (phospho Y15) antibody	Type: Rabbit monoclonal antibody Reactivity: Hu, Mo, Rt Applications: IHC-P, WB, IP	ab76146
	Anti-CDK2 (phospho T14) antibody	Type: Rabbit monoclonal antibody Reactivity: Hu, Rt, ChHa Applications: WB, IP, IHC-P, ICC	ab68265
	Anti-CDK2 (phospho T160) antibody	Type: Rabbit monoclonal antibody Reactivity: Hu, Mo, Rt ​Applications: IHC-P, WB	ab194868

Click here for the full list of Cdk 2 antibodies 

Cyclin B1

​​Cyclin B1 levels rise during G2 phase facilitating Cdk1-cyclin B1 complex formation^​6. Cdk1-cyclin B1 is activated by Cdc25 phosphatase⁷. Cyclin B1 is often found to be overexpressed in certain cancer types. 

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Click here for the full list of Cyclin B1 antibodies

Cyclin E1

Cdk2-cyclin E1 complex facilitates phosphorylation of retinoblastoma protein (Rb), E2F transcription factor release and DNA S phase entry⁸. 

Type	Reagent name	Description	AbID
Antibody	Anti-Cyclin E1 antibody ​	Type: Rabbit monoclonal antibody Reactivity: Hu Applications: WB, ICC/IF, Flow Cyt, IP	ab33911

Click here for the full list of Cyclin E1 antibodies

Cyclin A1

Cyclin A1 expression has been reported in several cancers⁹. p53 activates cyclin A1 promoter. Cdk2-cyclin A1 complex functions in DNA double strand break repair¹⁰.

Click here for the full list of Cyclin A1

Cdc25c

Cdc25 dephosphorylates Y15 and T14 on Cdk2, the rate-limiting step in Cdk activation/cell-cycle progression¹¹.

Type	Reagent name	Description	AbID
Antibody	Anti-Cdc25C antibody​	Type: Rabbit monoclonal antibody Reactivity: Hu Applications: WB, IHC-P, ICC/IF, Flow Cyt, IP	ab32444

Click here for the full list of Cdc25c antibodies

Cdc6

CDC6 has been associated with oncogenic activities in many types of cancer¹². Protein expression of Cdc6 increases during G1 phase. Cdc6 regulates initiation of DNA replication and its levels are stabilized by Cdk2-cyclin E activity¹³.

Click here for the full list of Cdc6 antibodies 

Cdk4/6 and cyclin D1/2

Required for efficient cell proliferation and playing a role in cancer formation¹⁴, kinase activity of Cdk4-cyclin D complex is inhibited by increase in p21 levels¹³. Cyclin D2 acts as a Cdk2 binding partner in absence of Cdk4 and Cdk6¹⁶.

Type	Reagent name	Description	AbID
Antibody	Anti-Cdk4 antibody​	Type: Rabbit monoclonal antibody Reactivity: Hu Applications: WB, IHC-P, Flow Cyt, ICC/IF	ab108357
	Anti-Cdk6 antibody	Type: Rabbit monoclonal antibody Reactivity: Hu Applications: Flow Cyt, ICC/IF, IHC-P, WB	ab124821
	Anti-Cyclin D1 antibody	Type: Rabbit monoclonal antibody Reactivity: Hu, Mo, Rt Applications: WB, IP, ICC/IF, IHC-P	ab134175
	Anti-Cyclin D2 antibody	Type: Rabbit monoclonal antibody Reactivity: Hu Applications: ICC/IF, IP, WB	ab207604

Click here for the full list of Cdk4 antibodies
Click here for the full list of Cdk6 antibodies
Click here for the full list of Cyclin D1 antibodies
​Click here for the full list of Cyclin D2 antibodies

Retinoblastoma protein (Rb)

Rb is inactivated following phosphorylation by Cdk2 and Cdk4/6. p21 inhibition of Cdk leads to dephosphorylation and activation of Rb. Rb forms a complex with E2F transcription factor and stalls cell cycle progression¹⁷. p21 both activates Rb by dephosphorylation and inactives it by degradation, leading to a negative feedback regulation of cell cycle checkpoint.

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