Cyclin Dependent Kinase-4
From Proteopedia
CDK4: Introduction
Cyclin Dependent Kinase-4 (CDK4) is a protein that is used in the cell cell cycle. The scene that is currently being shown here is when CDK4 is attached to its inhibitor, Cyclin D[1]. CDK4 by itself is just the green protein shown . This page will discuss the role of CDK4 in the cell cycle as well as CDK4's role in cancer.
Role in the Body
Cyclin Dependent Kinase-4 (CDK4) is activated by Cyclin D during the G1 Phase[2] after the G0 Phase[3] that some cells go into as a rest or dormant phase. There are three types of cyclin D: cyclin D1, cyclin D2, and cyclin D3. The CDK4-Cyclin D complexes are essential for entry in G1 phase. During the G1 Phase, a cell undergoes growth before having to divide again. Therefore, it is essential for the cell to undergo this growth in order for it to be big enough to divide.
Role in Cancer
It is known that CDK4 is over expressed in breast cancer. In an experiment by Yu, Qunyan, et al., mice were given cancer and then tested to see if the the CDK4 protein is over expressed. They found that a lack of CDK4 made mice resistant to breast cancer. Image:B.jpg In another experiment, they took mammary fad pads with high levels of D1-CDK4 complexes out of the mice and injected them with siRNA[4] which reduced the CDK4 levels. They found that the reduction of CDK4 blocked the ability for tumors to form. They occasionally found small tumors in the mice with siRNA infection; however, they also found high levels of CDK4 in those tumors.
Proteopedia Page Contributors and Editors (what is this?)
Cory Tiedeman, Michal Harel, Joel L. Sussman, Alexander Berchansky, David Canner, Ann Taylor
