Biochemical and cellular mechanisms of mammalian CDK inhibitors: a few unresolved issues

Xin-Hai Pei1, Yue Xiong

  • 1Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-7295, USA.

Oncogene
|April 20, 2005
PubMed

Insights

Cyclin-dependent kinase (CDK) inhibitors p21 and p16 are crucial for cell cycle control. While their mechanisms are understood, some aspects remain controversial.

Area of Science:

  • Molecular Biology
  • Cell Biology
  • Biochemistry

Background:

  • p21 and p16 are key proteins identified in CDK and cyclin complexes.
  • They represent distinct families of cyclin-dependent kinase (CDK) inhibitors in mammals.
  • These proteins are vital for linking cellular pathways to cell cycle regulation.

Purpose of the Study:

  • To review the known functions and mechanisms of p21 and p16.
  • To highlight the current understanding and remaining controversies surrounding these CDK inhibitors.

Main Methods:

  • Literature review of studies on p21 and p16.
  • Analysis of biochemical and cellular mechanisms.
  • Synthesis of existing research findings.

Main Results:

  • p21 and p16 are established as critical regulators of the cell cycle.
  • Extensive research has clarified many of their functions and interactions.
  • Certain aspects of their roles and regulation continue to be debated.

Conclusions:

  • The roles of p21 and p16 in cell cycle control are well-defined but complex.
  • Further research is needed to resolve outstanding questions regarding these CDK inhibitors.

Related Concept Videos

Inhibition of Cdk Activity02:34

Inhibition of Cdk Activity

The orderly progression of the cell cycle depends on the activation of Cdk protein by binding to its cyclin partner. However, the cell cycle must be restricted when undergoing abnormal changes. Most cancers correlate to the deregulated cell cycle, and since Cdks are a central component of the cell cycle, Cdk inhibitors are extensively studied to develop anticancer agents. For instance, cyclin D associates with several Cdks, such as Cdk 4/6, to form an active complex. The cyclin D-Cdk4/6 complex...
Inhibition of CDK Activity02:34

Inhibition of CDK Activity

The orderly progression of the cell cycle depends on the activation of Cdk protein by binding to its cyclin partner. However, the cell cycle must be restricted when undergoing abnormal changes. Most cancers correlate to the deregulated cell cycle, and since Cdks are a central component of the cell cycle, Cdk inhibitors are extensively studied to develop anticancer agents. For instance, cyclin D associates with several Cdks, such as Cdk 4/6, to form an active complex. The cyclin D-Cdk4/6 complex...
Positive Regulator Molecules02:39

Positive Regulator Molecules

Mitotic cell division results in daughter cells that exactly resemble the parent cell. However, errors in the DNA replication or distribution of genetic material may lead to genetic mutations that may be passed down to every new cell formed from the resulting abnormal cell. Propagation of such mutant cells is restricted through checkpoint mechanisms present at different stages of the cell cycle. These checkpoints involve regulator molecules that either promote or demote cell cycle events.
Positive Regulator Molecules01:45

Positive Regulator Molecules

To consistently produce healthy cells, the cell cycle—the process that generates daughter cells—must be precisely regulated.
M-Cdk Drives Transition Into Mitosis02:15

M-Cdk Drives Transition Into Mitosis

Checkpoints throughout the cell cycle serve as safeguards and gatekeepers, allowing the cell cycle to progress in favorable conditions and slow or halt it in problematic ones. This regulation is known as the cell cycle control system.
Cyclin-dependent kinases, or Cdks, work in concert with cyclins to control cell cycle transitions. M-Cdk, a complex of Cdk1 bound to M cyclin, is a well-known example of this coordinated control that drives the transition from the G2 to the M phase.
M cyclin...
M-Cdk Drives Transition Into Mitosis02:15

M-Cdk Drives Transition Into Mitosis

Checkpoints throughout the cell cycle serve as safeguards and gatekeepers, allowing the cell cycle to progress in favorable conditions and slow or halt it in problematic ones. This regulation is known as the cell cycle control system.
Cyclin-dependent kinases, or Cdks, work in concert with cyclins to control cell cycle transitions. M-Cdk, a complex of Cdk1 bound to M cyclin, is a well-known example of this coordinated control that drives the transition from the G2 to the M phase.
M cyclin...