Pocket protein family consists of three proteins: [1]
They play crucial roles in the metazoan cell cycle through interaction with members of the E2F transcription factors family.
The cell cycle, or cell-division cycle, is the series of events that take place in a cell that cause it to divide into two daughter cells. These events include the duplication of its DNA and some of its organelles, and subsequently the partitioning of its cytoplasm and other components into two daughter cells in a process called cell division.
A tumor suppressor gene (TSG), or anti-oncogene, is a gene that regulates a cell during cell division and replication. If the cell grows uncontrollably, it will result in cancer. When a tumor suppressor gene is mutated, it results in a loss or reduction in its function. In combination with other genetic mutations, this could allow the cell to grow abnormally. The loss of function for these genes may be even more significant in the development of human cancers, compared to the activation of oncogenes.
Retinoblastoma (Rb) is a rare form of cancer that rapidly develops from the immature cells of a retina, the light-detecting tissue of the eye. It is the most common primary malignant intraocular cancer in children, and it is almost exclusively found in young children.
E2F is a group of genes that encodes a family of transcription factors (TF) in higher eukaryotes. Three of them are activators: E2F1, 2 and E2F3a. Six others act as suppressors: E2F3b, E2F4-8. All of them are involved in the cell cycle regulation and synthesis of DNA in mammalian cells. E2Fs as TFs bind to the TTTCCCGC consensus binding site in the target promoter sequence.
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.
Cell division protein kinase 6 (CDK6) is an enzyme encoded by the CDK6 gene. It is regulated by cyclins, more specifically by Cyclin D proteins and Cyclin-dependent kinase inhibitor proteins. The protein encoded by this gene is a member of the cyclin-dependent kinase, (CDK) family, which includes CDK4. CDK family members are highly similar to the gene products of Saccharomyces cerevisiae cdc28, and Schizosaccharomyces pombe cdc2, and are known to be important regulators of cell cycle progression in the point of regulation named R or restriction point.
Transcription factor E2F1 is a protein that in humans is encoded by the E2F1 gene.
Retinoblastoma-like protein 2 is a protein that in humans is encoded by the RBL2 gene.
Transcription factor E2F4 is a protein that in humans is encoded by the E2F4 gene.
G1/S-specific cyclin-E1 is a protein that in humans is encoded by the CCNE1 gene.
Transcription factor E2F3 is a protein that in humans is encoded by the E2F3 gene.
Transcription factor E2F2 is a protein that in humans is encoded by the E2F2 gene.
Retinoblastoma-like 1 (p107), also known as RBL1, is a protein that in humans is encoded by the RBL1 gene.
HMG-box transcription factor 1, also known as HBP1, is a human protein.
AT-rich interactive domain-containing protein 3B is a protein that in humans is encoded by the ARID3B gene.
AT rich interactive domain 4A (RBP1-like), also known as ARID4A, is a protein which in humans is encoded by the ARID4A gene.
Fyn-related kinase is an enzyme that in humans is encoded by the FRK gene.
The Epstein–Barr virus nuclear antigen 3 (EBNA-3) is a family of viral proteins associated with the Epstein–Barr virus. A typical EBV genome contains three such proteins:
The retinoblastoma protein is a tumor suppressor protein that is dysfunctional in several major cancers. One function of pRb is to prevent excessive cell growth by inhibiting cell cycle progression until a cell is ready to divide. When the cell is ready to divide, pRb is phosphorylated, inactivating it, and the cell cycle is allowed to progress. It is also a recruiter of several chromatin remodeling enzymes such as methylases and acetylases.
Ed Harlow is an American molecular biologist.