Cell Cycle Regulation

Cell Cycle Regulation   Activation of Src by Protein-tyrosine phosphatase alpha Progression through the cell cycle is accompanied by activation of the proto-oncogene c-Src, a protein tyrosine kinase. Overexpression of Src leads to tyrosine phosphorylation of multiple protein substrates and cellular transformation. During inter ... AKAP95 role in mitosis and chromosome dynamics The chromatin packaging of the genome is dynamic, changing with the cell cycle and with transcriptional regulation. During mitosis, chromatin is condensed for segregation of chromosomes, while for transcription chromatin is more open. The nuclear m ... BTG family proteins and cell cycle regulation BTG2 is found to be one of the immediate early genes up-regulated by neural growth factor (NGF) and epidermal growth factor (EGF). Its transcriptional level is also up-regulated by p53, gamma radiation, adriamycin and UV treatment of cells. BTG seems ... cdc25 and chk1 Regulatory Pathway in response to DNA damage Cdc25 is a protein phosphatase responsible for dephosphorylating and activating cdc2, a crucial step in regulating the entry of all eukaryotic cells into the M-phase of the cell cycle. Cdc25 is phosphorylated throughout interphase but not in mitosis. ... CDK Regulation of DNA Replication Initiation of DNA replication in eukaryotes is a highly conserved, multi-step process (replication licensing) designed to restrict initiation events to once per replication origin per S phase. Its control has been uncovered by the discovery of the cy ... Cell Cycle: G1/S Check Point The G1/S cell cycle checkpoint controls the passage of eukaryotic cells from the first 'gap' phase (G1) into the DNA synthesis phase (S). Two cell cycle kinases, CDK4/6-cyclin D and CDK2-cyclin E, and the transcription complex that includes Rb and E2 ... Cell Cycle: G2/M Checkpoint The G2/M DNA damage checkpoint prevents the cell from entering mitosis (M phase) if the genome is damaged. The Cdc2-cyclin B kinase is pivotal in regulating this transition. During G2 phase, Cdc2 is maintained in an inactive state by the kinases Wee1 ... Cyclin E Destruction Pathway Cyclins are proteins that associate with cyclin-dependent protein kinases to regulate their activity and the progression of the cell cycle through specific checkpoints. Disruption of cyclin action can lead to either cell cycle arrest, or to uncontr ... Cyclins and Cell Cycle Regulation The cell cycle is regulated by the interplay of many molecules. Key among these are the cyclins which are expressed and then degraded in a concerted fashion to drive the stages of the cell cycle. Cyclins combine with cyclin dependent kinases (cdks) t ... Estrogen-responsive protein Efp controls cell cycle and breast tumors growth The estrogen-inducible RING finger protein Efp stimulates proliferation of breast cancer cells. 14-3-3 is p53-inducible protein that sequesters mitotic Cdks in the cytoplasm to inhibit entry into mitosis. To allow cell-cycle progression, estrogens st ... Hypoxia and p53 in the Cardiovascular system Hypoxic stress, like DNA damage, induces p53 protein accumulation and p53-dependent apoptosis in oncogenically transformed cells. Unlike DNA damage, hypoxia does not induce p53-dependent cell cycle arrest, suggesting that p53 activity is differential ... Influence of Ras and Rho proteins on G1 to S Transition The cell cycle transition from G1 to S phase is a key regulatory point in the cell cycle. This transition is regulated by the checkpoint kinase cdk2 that activates the G1 to S transition when it is associated with cyclin E. Cdk2/Cyclin E causes the ... Meiotic Arrest in Oogenesis Mammalian oogenesis is marked by a prolonged pause in meiosis II that can last many years for human oocytes. This meiotic arrest is not released to complete meiosis until after fertilization, at which time the second polar body is released, and the ... p53 Signaling Pathway p53 is a transcription factor who's activity is regulated by phosphorylation. The function is p53 is to keep the cell from progressing through the cell cycle if there is damage to DNA present. It may do this in multiple ways from holding the cell at ... Protein Kinase A at the Centrosome Protein kinase A regulatory subunit RIIalpha (PKA-RIIa) is tightly bound to centrosomal structures during interphase through interaction with the A-kinase anchoring protein AKAP350 (also known as AKAP450 and CGNAP), MAP2 and Pericentrin. This diagra ... PTEN dependent cell cycle arrest and apoptosis PTEN is a tumor suppressor gene. Recombinant PTEN is capable of dephosphorylating phosphatidylinositol 3,4,5-triphosphate[PI(3,4,5)P3], the product of phosphatidylinositol 3 -kinase. Many of the cancer-related mutations have been mapped to the phosph ... RB Tumor Suppressor/Checkpoint Signaling in response to DNA damage Cell cycle checkpoint controls at the G1 to S transition and the G2 to M transition prevent the cell cycle from progressing when DNA is damaged. The ATM protein kinase detects DNA damage and in response to this activates DNA repair factors and inhibi ... Regulation of cell cycle progression by Plk3 The focus of this pathway is to illustrate the role of Polo-like Kinase 3 (Plk3 also known as Prk and Fnk) as part of the regulatory cascade leading to apoptosis and the arrest cell cycle progression prior to M phase. Phosphorlyation of Cdc25C on se ... Regulation of p27 Phosphorylation during Cell Cycle Progression p27/Kip1 regulates the cell cycle by inhibiting the checkpoint kinase cdk2/cyclin E and blocking cell cycle progression through the G1-S transition. Cancer cells in some cases have reduced levels of p27, supporting the importance of p27 in cell cycl ... Regulation of Splicing through Sam68 While transcriptional regulation is often viewed as the most prevalent way extracellular signals to regulate gene expression, post-transcriptional regulation of splicing, RNA stability, and translation are also regulated by extracellular signals. Sa ... Role of BRCA1, BRCA2 and ATR in Cancer Susceptibility BRCA1 and BRCA2 were identified genetically as breast cancer susceptibility genes when a single copy of the gene is mutated and are involved in the cellular response to DNA damage, including blocking cell cycle progression and inducing DNA repair to ... Role of Ran in mitotic spindle regulation One of the central features of mitotic cell division is the formation of the spindle that segregates chromosomes into each daughter cell. Chromosomes are not just passengers along for a ride with the spindle, but active participants in the nucleatio ... Sonic Hedgehog (SHH) Receptor Ptc1 Regulates cell cycle Sonic Hedgehog (Shh) is a secreted protein identified genetically as an important developmental factor. Shh provides a morphogenic signal in the developing CNS, organizing the spatial patterning of cells in the midbrain and inducing proliferation of ... Stathmin and breast cancer resistance to antimicrotubule agents Stathmin is a ubiquitous, cytosolic 19-kDa protein, which is phosphorylated on up to four sites in response to many regulatory signals within cells. Its molecular characterization indicates a functional organization including an N-terminal regulatory ... Telomeres, Telomerase, Cellular Aging, and Immortality Telomeres, which define the ends of chromosomes, consist of short, tandemly repeated DNA sequences loosely conserved in eukaryotes. Telomerase is a ribonucleoprotein complex ( we only show a few of the components in this illustration) which in vitro ... Tumor Suppressor Arf Inhibits Ribosomal Biogenesis Cyclin-dependent kinase inhibitor-2A (CDKN2A) goes by the colloquial designation p16, which is sometimes referred to as p16(INK4). The alpha transcript of CDKN2A has been shown to encode p16(INK4a), a recognized tumor suppressor that induces a G1 cel ...

Privacy Policy | Disclaimer | Terms & Conditions | Sponsor Information