Cyclin-dependent kinase 4 also known as cell division protein kinase 4 is an enzyme that in humans is encoded by the CDK4 gene. CDK4 is a member of the cyclin-dependent kinase family. The protein encoded by this gene is a member of the Ser/Thr protein kinase family. This protein is highly similar to the gene products of S. cerevisiae cdc28 and S. pombe cdc2. It is a catalytic subunit of the protein kinase complex that is important for cell cycle G1 phase progression. The activity of this kinase is restricted to the G1-S phase, which is controlled by the regulatory subunits D-type cyclins and CDK inhibitor p16INK4a. This kinase was shown to be responsible for the phosphorylation of retinoblastoma gene product (Rb). Ser/Thr-kinase component of cyclin D-CDK4 (DC) complexes that phosphorylate and inhibit members of the retinoblastoma (RB) protein family including RB1 and regulate the cell-cycle during G1/S transition. Phosphorylation of RB1 allows dissociation of the transcription factor E2F from the RB/E2F complexes and the subsequent transcription of E2F target genes which are responsible for the progression through the G1phase. Hypophosphorylates RB1 in early G1 phase. Cyclin D-CDK4 complexes are major integrators of various mitogenenic and antimitogenic signals. Also phosphorylates SMAD3 in a cell-cycle-dependent manner and represses its transcriptional activity. Component of the ternary complex, cyclin D/CDK4/CDKN1B, required for nuclear translocation and activity of the cyclin D-CDK4 complex.
Cdk4 Polyclonal Antibody was affinity-purified from rabbit antiserum by affinity-chromatography using epitope-specific immunogen. This antibody has been tested with WB, IHC-p and ELISA. And Abbkine suggested starting dilutions are as follows: WB: 1:500-1:2000, IHC-p: 1:100-300 ELISA: 1:20000.
CDKs is the central molecule in regulating cell cycles. It coordinate with Cyclins and CDKIs and forms complex network with signaling pathways of cell checkpoint,affecting the process of cell cycles. Any abnormally in the regulating network whose center is CDKs will result in abnormality in cell cycles and eventually leads to the occurrence of tumor. This field has been the focus of many cell biology and cancer biology researches. We choose Cdk4 Polyclonal Antibody as primary antibody in Western-blot, the results are satisfactory.