The G/G genotype of the Bcl1 polymorphism was significantly ......
The G/G genotype of the Bcl1 polymorphism was significantly more common (p<0.03) in women with major depression (n=52) than in controls (n=29).More...
Positive relationships between CCND1 and other components at different levels (count: 0)
Positive relationship network of CCND1 in MK4MDD
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Note:
1. The different color of the nodes denotes the level of the nodes.
Genetic/Epigenetic Locus
Protein and Other Molecule
Cell and Molecular Pathway
Neural System
Cognition and Behavior
Symptoms and Signs
Environment
MDD
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If the mapped gene or protein is not from literature, square node would be used instead of Circle node.
Accordingly, the relationship is marked with dot line.
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3. The network is generated using Cytoscape Web
Negative relationships between CCND1 and MDD (count: 0)
Negative relationships between CCND1 and other components at different levels (count: 0)
Cell-matrix adhesions play essential roles in important biol......
Cell-matrix adhesions play essential roles in important biological processes including cell motility, cell proliferation, cell differentiation, regulation of gene expression and cell survival. At the cell-extracellular matrix contact points, specialized structures are formed and termed focal adhesions, where bundles of actin filaments are anchored to transmembrane receptors of the integrin family through a multi-molecular complex of junctional plaque proteins. Some of the constituents of focal adhesions participate in the structural link between membrane receptors and the actin cytoskeleton, while others are signalling molecules, including different protein kinases and phosphatases, their substrates, and various adapter proteins. Integrin signaling is dependent upon the non-receptor tyrosine kinase activities of the FAK and src proteins as well as the adaptor protein functions of FAK, src and Shc to initiate downstream signaling events. These signalling events culminate in reorganization of the actin cytoskeleton; a prerequisite for changes in cell shape and motility, and gene expression. Similar morphological alterations and modulation of gene expression are initiated by the binding of growth factors to their respective receptors, emphasizing the considerable crosstalk between adhesion- and growth factor-mediated signalling.More...
Myocarditis is a cardiac disease associated with inflammatio......
Myocarditis is a cardiac disease associated with inflammation and injury of the myocardium. It results from various etiologies, both noninfectious and infectious, but coxsackievirus B3 (CVB3) is still considered the dominant etiological agent. Myocarditis may be caused by direct cytopathic effects of virus, a pathologic immune response to persistent virus, or autoimmunity triggered by the viral infection. The virus enters the myocyte through internalization of the coxsackie-adenoviral receptor (CAR) and its coreceptor, decay-accelerating factor (DAF). Viral proteases cleave various proteins in the host cell. One example is viral protease 2A, which cleaves eukaryote initiation factor 4G (eIF4G) and the dystrophin protein, resulting in a complete shutdown of cap-dependent RNA translation and cytoskeletal destruction in infected cardiomyocytes, respectively. CVB3 also cleaves the member of the Bcl-2 family Bid, leading to apoptosis. CVB3 infection also induces the cleavage of cyclin D protein through a proteasome-dependent pathway, leading to the host cell-growth arrest. Viral infection and necrosis of myocytes may lead to the release of intracellular antigens, resulting in activation of self-reactive T cells. CVB infection is a significant cause of dilated cardiomyopathy (DCM) as well as myocarditis. Epidemiologically, myocarditis underlies a significant portion of patients with DCM.More...
Bladder cancer arise and progress along two distinctive path......
Bladder cancer arise and progress along two distinctive pathways. The first of these is often preceded by simple and papillary hyperplasia and exhibits a tumour morphology that is low-grade, superficial and papillary. Papillary carcinoma has a tendency to recur locally, but rarely invades and metastasizes. These tumors frequently show a constitutive activation of the receptor tyrosine kinase-Ras pathway, exhibiting activating mutations in the HRAS and fibroblast growth factor receptor 3 (FGFR3) genes. The second tumour pathway is characterized by high-grade muscle-invasive tumours, which either originate from flat carcinoma in situ (CIS)/severe dysplasia or arise de novo. Over half of these tumours show defects in the tumour suppressors p53 and/or the retinoblastoma protein (RB) genes and pathways, and over 50% of these tumours progress to local and distant metastases. Some of the cell cycle-related molecules show evidence of epigenetic modulation through aberrant promoter hypermethylation in invasive bladder cancer. Invasion and metastases are promoted by several factors that alter the tumour microenvironment, including the aberrant expression of E-cadherins (E-cad), matrix metalloproteinases (MMPs), angiogenic factors such as vascular endothelial growth factor (VEGF).More...
Classically, colorectal cancer (CRC) has been believed to de......
Classically, colorectal cancer (CRC) has been believed to develop from normal mucosa through the premalignant adenoma by the step-wise accumulation of mutations. All CRC display either microsatellite instability (MSI) or chromosome instability (CIN). MSI occurs in 15% of colon cancers and results from inactivation of the DNA mismatch repair (MMR) system by either MMR gene mutations or hypermethylation of the MLH1 promoter. MSI promotes tumorigenesis through generating mutations in target genes that possess coding microsatellite repeats, such as beta-catenin, TGFBR2 and BAX. CIN is found in the majority of colon cancers and leads to a different pattern of gene alterations that contribute to tumor formation. Genes involved in CIN are those coding for APC, K-ras, SMAD4 and p53.More...
Two major types of genetic events are crucial for the molecu......
Two major types of genetic events are crucial for the molecular pathogenesis of acute myeloid leukemias (AML) : activating mutations of signal transduction intermediates and alterations in myeloid transcription factors governing hematopoietic differentiation. Both aberrant and constitutive activation of signal transduction molecules are found in about 50% of primary AML bone marrow samples, and seem to contribute to the increased proliferation and apoptosis resistance. The most common of these activating events were observed in the RTK Flt3, in N-Ras and K-Ras, in Kit, and sporadically in other RTKs. Specific haematopoietic transcription factors are crucial for differentiation to particular lineages during normal differentiation, but are frequently disrupted in AML. Some mechanisms of disruption involve the effect of fusion proteins that are generated by chromosomal translocations on haematopoietic transcription factors. In other cases, the transcription factors themselves are mutated.More...
The Janus kinase/signal transducers and activators of transc......
The Janus kinase/signal transducers and activators of transcription (JAK/STAT) pathway is one of a handful of pleiotropic cascades used to transduce a multitude of signals for development and homeostasis in animals, from humans to flies. In mammals, the JAK/STAT pathway is the principal signaling mechanism for a wide array of cytokines and growth factors. Following the binding of cytokines to their cognate receptor, STATs are activated by members of the JAK family of tyrosine kinases. Once activated, they dimerize and translocate to the nucleus and modulate the expression of target genes. In addition to the activation of STATs, JAKs mediate the recruitment of other molecules such as the MAP kinases, PI3 kinase etc. These molecules process downstream signals via the Ras-Raf-MAP kinase and PI3 kinase pathways which results in the activation of additional transcription factors.More...
Two types of endometrial carcinoma are distinguished with re......
Two types of endometrial carcinoma are distinguished with respect to biology and clinical course. Type-I carcinoma is related to hyperestrogenism by association with endometrial hyperplasia, frequent expression of estrogen and progesterone receptors and younger age, whereas type-II carcinoma is unrelated to estrogen, associated with atrophic endometrium, frequent lack of estrogen and progesterone receptors and older age. This classification has also been justified at the molecular level with Type 1 tumours being more commonly associated with abnormalities of DNA-mismatch repair genes, K-ras, PTEN and beta-catenin, and Type 2 tumours with abnormalities of p53 and HER2/neu.More...
The identification of key molecular alterations in prostate-......
The identification of key molecular alterations in prostate-cancer cells implicates carcinogen defenses (GSTP1), growth-factor-signaling pathways (NKX3.1, PTEN, and p27), and androgens (AR) as critical determinants of the phenotype of prostate-cancer cells. Glutathione S-transferases (GSTP1) are detoxifying enzymes that catalyze conjunction of glutathione with harmful, electrophilic molecules, thereby protecting cells from carcinogenic factors. Cells of prostatic intraepithelial neoplasia, devoid of GSTP1, undergo genomic damage mediated by such carcinogens. NKX3.1, PTEN, and p27 regulate the growth and survival of prostate cells in the normal prostate. Inadequate levels of PTEN and NKX3.1 lead to a reduction in p27 levels and to increased proliferation and decreased apoptosis. After therapeutic reduction in the levels of testosterone and dihydrotestosterone, the emergence of androgen-independent prostate cancer has been associated with mutations in the androgen receptor (AR) that permit receptor activation by other ligands, increased expression of androgen receptors accompanying AR amplification, and ligand-independent androgen-receptor activation.More...
Papillary thyroid carcinoma (PTC), the most frequent neoplas......
Papillary thyroid carcinoma (PTC), the most frequent neoplasia originating from the thyroid epithelium, accounts for about 80% of all thyroid cancers. Chimeric oncogenes, created by chromosomal rearrangements involving prevalently RET and, to a less extent, NTRK1 loci, are implicated in the development of papillary carcinoma.These are inappropriately expressed and stimulate constitutive signaling, bypassing the need for receptor activation by growth factors. Alternatively, mutant RAS directly stimulates BRAF, whereas mutant BRAF directly stimulates MEK. Of all thyroid cancers, 15-20% are follicular thyroid carcinoma (FTC). The most distinctive molecular features of follicular carcinoma are the prominence of aneuploidy and the high prevalence of RAS mutations and PAX8-PPAR-gamma rearrangements. The PPAR-gamma rearrangement functions through a dominant-negative effect on the transcriptional activity of wild-type PPAR-gamma. The fusion oncoprotein contributes to malignant transformation by targeting several cellular pathways, some of which are normally engaged by PPAR-gamma. Most poorly differentiated and undifferentiated thyroid carcinomas are considered to derive from pre-existing well-differentiated thyroid carcinoma through additional genetic events, including beta-catenin nuclear accumulation and p53 inactivation, but de novo occurrence might also occur.More...
Chronic myelogenous leukaemia (CML) is a biphasic disease, i......
Chronic myelogenous leukaemia (CML) is a biphasic disease, initiated by expression of the BCR/ABL fusion gene product in self-renewing, haematopoietic stem cells (HSCs). HSCs can differentiate into common myeloid progenitors (CMPs), which then differentiate into granulocyte/macrophage progenitors (GMPs). HSCs can also differentiate into common lymphoid progenitors (CLPs), which are the progenitors of lymphocytes such as T cells and B cells. The initial chronic phase of CML (CML-CP) is characterized by a massive expansion of the granulocytic-cell series. Acquisition of additional genetic mutations beyond expression of BCR/ABL causes the progression of CML from chronic phase to blast phase (CML-BP), characterized by an accumulation of myeloid or lymphoid blast cells. The BCR/ABL fusion gene encodes p210BCR/ABL, an oncoprotein, which, unlike the normal p145 c-Abl, has constitutive tyrosine kinase activity and is predominantly localized in the cytoplasm. The tyrosine kinase activity is essential for cell transformation and the cytoplasmic localization of BCR/ABL allows the assembly of phosphorylated substrates in multiprotein complexes that transmit mitogenic and antiapoptotic signals. Additional cytogenetic and molecular changes are frequently found in patients with CML during the progression of the disease from chronic to blast phase. Some of the genetic changes include mutations in TP53, RB, and CDKN2A (also known as p16INK4A), or overexpression of genes such as EVI1. Additional chromosome translocations are also observed, such as t(3;21)(q26;q22), which generates AML1/EVI1. AML1/EVI-1 represses TGF-beta-mediated growth inhibitory signal.More...
Wnt proteins are secreted morphogens that are required for b......
Wnt proteins are secreted morphogens that are required for basic developmental processes, such as cell-fate specification, progenitor-cell proliferation and the control of asymmetric cell division, in many different species and organs. There are at least three different Wnt pathways: the canonical pathway, the planar cell polarity (PCP) pathway and the Wnt/Ca2+ pathway. In the canonical Wnt pathway, the major effect of Wnt ligand binding to its receptor is the stabilization of cytoplasmic beta-catenin through inhibition of the bea-catenin degradation complex. Beta-catenin is then free to enter the nucleus and activate Wnt-regulated genes through its interaction with TCF (T-cell factor) family transcription factors and concomitant recruitment of coactivators. Planar cell polarity (PCP) signaling leads to the activation of the small GTPases RHOA (RAS homologue gene-family member A) and RAC1, which activate the stress kinase JNK (Jun N-terminal kinase) and ROCK (RHO-associated coiled-coil-containing protein kinase 1) and leads to remodelling of the cytoskeleton and changes in cell adhesion and motility. WNT-Ca2+ signalling is mediated through G proteins and phospholipases and leads to transient increases in cytoplasmic free calcium that subsequently activate the kinase PKC (protein kinase C) and CAMKII (calcium calmodulin mediated kinase II) and the phosphatase calcineurin.More...
Glioblastoma multiforme (GBM) formation is either de novo (p......
Glioblastoma multiforme (GBM) formation is either de novo (primary GBMs) or due to the progression of a lower grade glioma to a higher grade one through the acquisition of additional mutations (secondary GBMs). In primary GBM, disruption of the p53 pathway often occurs through loss of ARF, or less frequently through amplification of MDM2. Disruption of the RB pathway occurs through loss of INK4A. Amplification and/or mutation of the epidermal growth factor receptor (EGFR) is the most frequently detected genetic defect that is associated with primary GBM. In secondary GBM, loss of p53 and activation of the growth-factorreceptor-tyrosine-kinase signalling pathway (such as through overexpression of PDGF/PDGFR ) initiates tumour formation,whereas disruption of the retinoblastoma (RB) pathway contributes to the progression of tumour development. Loss of PTEN has been implicated in both pathways, although it is much more common in the pathogenesis of primary GBM.More...
Normal duct epithelium progresses to infiltrating cancer thr......
Normal duct epithelium progresses to infiltrating cancer through a series of histologically defined precursors (PanINs). The overexpression of HER-2/neu and activating point mutations in the K-ras gene occur early, inactivation of the p16 gene at an intermediate stage, and the inactivation of p53, SMAD4, and BRCA2 occur relatively late. Activated K-ras engages multiple effector pathways. Although EGF receptors are conventionally regarded as upstream activators of RAS proteins, they can also act as RAS signal transducers via RAS-induced autocrine activation of the EGFR family ligands. Pancreatic ductal adenocarcinoma (PDA) show elevated expression of EGF receptors (e.g. HER2/neu) and their ligands (e.g.TGF-alpha) consistent with the presence of this autocrine loop. Moreover, PDA shows extensive genomic instability and aneuploidy. Telomere attrition and mutations in p53 and BRCA2 are likely to contribute to these phenotypes. Inactivation of the SMAD4 tumour suppressor gene leads to loss of the inhibitory influence of the transforming growth factor-beta signalling pathway.More...
Five distinct stages have been proposed in the evolution of ......
Five distinct stages have been proposed in the evolution of melanoma on the basis of histological criteria: common acquired and congenital nevi without dysplastic changes; dysplastic nevi with structural and architectural atypia; radial-growth phase (RGP) melanoma; vertical-growth phase (VGP) melanoma; and metastatic melanoma. Oncogenic NRAS mutations activate both effector pathways Raf-MEK-ERK and PI3K-Akt. The Raf-MEK-ERK pathway may also be activated via mutations in the BRAF gene. The PI3K-Akt pathway may be activated through loss or mutation of the inhibitory tumor suppressor gene PTEN. These mutations arise early during melanoma pathogenesis and are preserved throughout tumor progression. Moreover, melanoma development is strongly associated with inactivation of the p16INK4a/CDK4,6/pRb and p14ARF/HMD2/p53 tumor suppressor pathways. The vertical-growth phase and metastatic melanoma are notable for striking changes in the control of cell adhesion. Recently, amplification of the MITF gene was demonstrated in 10% of primary melanomas and 20% of metastatic melanomas, suggesting that MITF is a melanoma oncogene.More...
Non-small-cell lung cancer (NSCLC) accounts for approximatel......
Non-small-cell lung cancer (NSCLC) accounts for approximately 80% of lung cancer and represents a heterogeneous group of cancers, consisting mainly of squamous cell (SCC), adeno (AC) and large-cell carcinoma. Molecular mechanisms altered in NSCLC include activation of oncogenes, such as K-RAS and c-erbB-2, and inactivation of tumorsuppressor genes, such as p53, p16INK4a, RAR-beta, and RASSF1. Point mutations within the K-RAS gene inactivate GTPase activity and the p21-RAS protein continuously transmits growth signals to the nucleus. Overexpression of c-erbB-2 or EGFR leads to a proliferative advantage. Inactivating mutation of p53 can lead to more rapid proliferation and reduced apoptosis. The protein encoded by the p16INK4a inhibits formation of CDK-cyclin-D complexes by competitive binding of CDK4 and CDK6. Loss of p16INK4a expression is a common feature of NSCLC RAR-beta is a nuclear receptor that bears vitamin-A-dependent transcriptional activity. RASSF1A is able to form heterodimers with Nore-1, an RAS effector.Therefore loss of RASSF1A might shift the balance of RAS activity towards a growth-promoting effect.More...
p53 activation is induced by a number of stress signals, inc......
p53 activation is induced by a number of stress signals, including DNA damage, oxidative stress and activated oncogenes. The p53 protein is employed as a transcriptional activator of p53-regulated genes. This results in three major outputs; cell cycle arrest, cellular senescence or apoptosis. Other p53-regulated gene functions communicate with adjacent cells, repair the damaged DNA or set up positive and negative feedback loops that enhance or attenuate the functions of the p53 protein and integrate these stress responses with other signal transduction pathways.More...
Small cell lung carcinoma (SCLC) is a highly aggressive neop......
Small cell lung carcinoma (SCLC) is a highly aggressive neoplasm, which accounts for approximately 20% of all lung cancer cases. Molecular mechanisms altered in SCLC include induced expression of oncogene, MYC, and loss of tumorsuppressor genes, such as p53, PTEN, RB, and FHIT. The overexpression of MYC proteins in SCLC is largely a result of gene amplification. Such overexpression leads to more rapid proliferation and loss of terminal differentiation. Mutation or deletion of p53 or PTEN can lead to more rapid proliferation and reduced apoptosis. The retinoblastoma gene RB1 encodes a nuclear phosphoprotein that helps to regulate cell-cycle progression. The fragile histidine triad gene FHIT encodes the enzyme diadenosine triphosphate hydrolase, which is thought to have an indirect role in proapoptosis and cell-cycle control.More...
Mitotic cell cycle progression is accomplished through a rep......
Mitotic cell cycle progression is accomplished through a reproducible sequence of events, DNA replication (S phase) and mitosis (M phase) separated temporally by gaps known as G1 and G2 phases. Cyclin-dependent kinases (CDKs) are key regulatory enzymes, each consisting of a catalytic CDK subunit and an activating cyclin subunit. CDKs regulate the cell's progression through the phases of the cell cycle by modulating the activity of key substrates. Downstream targets of CDKs include transcription factor E2F and its regulator Rb. Precise activation and inactivation of CDKs at specific points in the cell cycle are required for orderly cell division. Cyclin-CDK inhibitors (CKIs), such as p16Ink4a, p15Ink4b, p27Kip1, and p21Cip1, are involved in the negative regulation of CDK activities, thus providing a pathway through which the cell cycle is negatively regulated. Eukaryotic cells respond to DNA damage by activating signaling pathways that promote cell cycle arrest and DNA repair. In response to DNA damage, the checkpoint kinase ATM phosphorylates and activates Chk2, which in turn directly phosphorylates and activates p53 tumor suppressor protein. p53 and its transcriptional targets play an important role in both G1 and G2 checkpoints. ATR-Chk1-mediated protein degradation of Cdc25A protein phosphatase is also a mechanism conferring intra-S-phase checkpoint activation.More...
The G1/S cell cycle checkpoint controls the passage of eukar......
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 E2F are pivotal in controlling this checkpoint. During G1 phase, the Rb-HDAC repressor complex binds to the E2F-DP1 transcription factors, inhibiting the downstream transcription. Phosphorylation of Rb by CDK4/6 and CDK2 dissociates the Rb-repressor complex, permitting transcription of S-phase genes encoding for proteins that amplify the G1 to S phase switch and that are required for DNA replication. Many different stimuli exert checkpoint control including TGFb, DNA damage, contact inhibition, replicative senescence, and growth factor withdrawal. The first four act by inducing members of the INK4 or Kip/Cip families of cell cycle kinase inhibitors. TGFb additionally inhibits the transcription of Cdc25A, a phosphatase that activates the cell cycle kinases. Growth factor withdrawal activates GSK3b, which phosphorylates cyclin D, leading to its rapid ubiquitination and proteosomal degradation. Ubiquitination, nuclear export, and degradation are mechanisms commonly used to rapidly reduce the concentration of cell-cycle control proteins.More...
Wnt family members are secreted glycoproteins who bind to ce......
Wnt family members are secreted glycoproteins who bind to cell surface receptors such as Frizzled. Wnt members can play a role in the expression of many genes by interacting with multiple disparate signaling pathways. Shown is the Wnt/beta-catenin pathway.More...
Several forms of post-translational modification regulate pr......
Several forms of post-translational modification regulate protein activities. Recently, protein methylation by CARM1 (coactivator-associated arginine methyltransferase 1) has been observed to play a key role in transcriptional regulation. CARM1 associates with the p160 class of transcriptional coactivators involved in gene activation by steroid hormone family receptors. CARM1 also interacts with CBP/p300 transcriptional coactivators involved in gene activation by a large variety of transcription factors, including steroid hormone receptors and CEBP. One target of CARM1 is the core histones H3 and H4, which are also targets of the histone acetylase activity of CBP/p300 coactivators. Recruitment of CARM1 to the promoter region by binding to coactivators increases histone methylation and makes promoter regions more accessible for transcription. Another target of CARM1 methylation is a coactivator it interacts with, CBP. Methylation of CBP by CARM1 blocks CBP from acting as a coactivator for CREB and redirects the limited CBP pool in the cell to be available for steroid hormone receptors. Other forms of post-translational protein modification such as phosphorylation are reversible in nature, but as of yet a protein demethylase is not known. The methylation activity of CARM1 modulates the activity of specific transcriptional regulators. CARM1 acts as a coactivator for the myogenic transcription factor Mef2c, and is necessary for normal muscle cell differentiation. The estrogen receptor is another transcription factor that uses CARM1 as one of several coactivators, acting synergistically with CBP through the Grip1 member of the p160 family of coactivators. The interaction of estrogen receptor with various ligand-dependent coactivators may produce the tissue selective response of some estrogen receptor ligands like tamoxifen.More...
The cell cycle is regulated by the interplay of many molecul......
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) to form activated kinases that phosphorylate targets leading to cell cycle regulation. A breakdown in the regulation of this cycle can lead to out of control growth and contribute to tumor formation. Defects in many of the molecules that regulate the cell cycle have been implicated in cancer. Key among these are p53, the cdk inhibitors (p15, p16, p18, p19, p21, p27), and Rb, all of which act to keep the cell cycle from progressing until all repairs to damaged DNA have been completed.More...
Inactivation of Gsk3 by AKT causes accumulation of b-catenin in Alveolar Macrophages
Lipopolysaccharide. One of the key actions of AKT is to bloc......
Lipopolysaccharide. One of the key actions of AKT is to block apoptosis. AKT phosphorylation of NF-kB promotes the survival and activation of macrophages responding to LPS. Another substrate of AKT is the protein kinase Gsk3-beta. AKT phosphorylates and deactivates Gsk3-beta. Non-phosphorylated Gsk3-beta is active and phosphorylates beta-catenin, leading to its degradation in the ubiquitin dependent proteosome pathway. Stimulation by LPS causes the accumulation of beta-catenin in the nucleus and the activation of genes in concert with the transcription factor LEF1. This pathway is probably not restricted to alveolar pathway, but leads to the activation of beta-catenin dependent genes by LPS in other cells as well. Other pathways regulate this pathway also, such as the modulation of PI3 kinase activity by ceramide, and the inhibition of Gsk3-beta activity by the Wnt/frizzled/disheveled (DSH) pathway.More...
p53 is a transcription factor who's activity is regulated by......
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 a checkpoint until repairs can be made to causing the cell to enter apoptosis if the damage cannot be repaired. The critical role of p53 is evidenced by the fact that it is mutated in a very large fraction of tumors from nearly all sources.More...
Influence of Ras and Rho proteins on G1 to S Transition
The cell cycle transition from G1 to S phase is a key regula......
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 G1 to S transition through phosphorylation of the tumor suppressor Rb, releasing the transcription factor E2F-1. Other pathways acting through Rac, Ras and Rho also regulate the G1 to S transition. Ras regulates cyclin D1 expression to affect the G1 to S transition. Transforming forms of Ras or Raf induce cyclin D1 expression and cause early entry into S phase. Signaling from Ras to Raf to MEK to ERKs induces Cyclin D1 expression, allowing Cyclin D1 to complex with Cdk4 and Cdk6 and phosphorylate Rb. Rac-1 and PAK appear to induce Cyclin D1 expression and induce the G1 to S transition primarily through activation of NF-kB to activate the Cyclin D1 promoter. Rho activates cdk2 and also inhibits p21 and p27 to induce cyclin D1 and stimulate the G1 to S transition. Rho represses p21 expression to block p21 induction by Ras and to allow Ras induced progression from G1 to S. Cells that lack p21 do not require Rho for Ras to induce cell cycle progression from G1 to S phase. The cooperative action of Ras, Rac and Rho to induce Cyclin D1 expression is a key component of oncogenic transformation.More...
DNA synthesis occurs in the S phase, or the synthesis phase,......
DNA synthesis occurs in the S phase, or the synthesis phase, of the cell cycle. The cell duplicates its hereditary material, and two copies of the chromosome are formed. As DNA replication continues, the E type cyclins shared by the G1 and S phases, are destroyed and the levels of the mitotic cyclins rise.More...
Early cell cycle progression in G1 is under the control of t......
Early cell cycle progression in G1 is under the control of the D-type cyclins together with Cdk4 and Cdk6. An important target for these CDKs is the Retinoblastoma (Rb) protein, which when phosphorylated promotes cell cycle progression by releasing E2F transcription factors that transactivate several important genes for later cell cycle events. The formation of Cyclin D - Cdk4/6 complexes is promoted by two proteins, p21Cip1/Waf1 and p27kip1, and their activity can be inhibited by the binding of several small CDK-inhibitory proteins (CKIs): p15INK4B, p16INK4A, p18INK4C and p19INK4D.More...
The replication of the genome and the subsequent segregation......
The replication of the genome and the subsequent segregation of chromosomes into daughter cells are controlled by a series of events collectively known as the cell cycle. DNA replication is carried out during a discrete temporal period known as the S (synthesis)-phase, and chromosome segregation occurs during a massive reorganization to cellular architecture at mitosis. Two gap-phases separate these major cell cycle events: G1 between mitosis and S-phase, and G2 between S-phase and mitosis. In the development of the human body, cells can exit the cell cycle for a period and enter a quiescent state known as G0, or terminally differentiate into cells that will not divide again, but undergo morphological development to carry out the wide variety of specialized functions of individual tissues. A family of protein serine/threonine kinases known as the cyclin-dependent kinases (CDKs) controls progression through the cell cycle. As the name suggests, the activity of the catalytic subunit is dependent on binding to a cyclin partner. The human genome encodes several cyclins and several CDKs, with their names largely derived from the order in which they were identified. The oscillation of cyclin abundance is one important mechanism by which these enzymes phosphorylate key substrates to promote events at the relevant time and place. Additional regulatory proteins and post-translational modifications ensure that CDK activity is precisely regulated, frequently confined to a narrow window of activity.More...
CCND1 related interactors from protein-protein interaction data in HPRD (count: 40)