NAD(H)-binding proteins play important roles in cell-cycle and developmental signaling in eukaryotes. We identified a bifunctional NAD(H)-binding regulator (KidO) that integrates cell-fate signaling with cytokinesis in the bacterium Caulobacter crescentus. KidO stimulates the DivJ kinase and directly acts on the cytokinetic tubulin, FtsZ, to tune cytokinesis with the cell cycle. ...

Previously, we have identified a novel centrosomal protein centrobin that asymmetrically localizes to the daughter centriole. We found that depletion of centrobin expression inhibited the centriole duplication and impaired cytokinesis. However, the biological significance of centrobin in the cell cycle remains unknown. In the current study, we observed that silencing ...

In the present study, we demonstrated that gadolinium-containing particles formed in cell culture medium acted as a biologically active entity to mediate cell cycle progression in NIH3T3 cells. The particles were observed to accumulate at the cell surface by scanning electron microscopy. Energy-dispersive X-ray analysis was undertaken and confirmed that ...

AIMS: Adult mammalian cardiomyocytes are traditionally viewed as being permanently withdrawn from the cell cycle. Whereas some groups have reported none, others have reported extensive mitosis in adult myocardium under steady-state conditions. Recently, a highly specific assay of 14C dating in humans has suggested a continuous generation of cardiomyocytes in ...

Prostaglandin E(2) (PGE(2)), one of the downstream products of cyclooxygenase-2 enzymatic activity, promotes colorectal carcinogenesis in part by stimulating cell division. In this study, we define a critical mechanism in this process by showing that the prometastatic adapter protein human enhancer of filamentation 1 (HEF1; NEDD9) links PGE(2) to the ...

Paranucleospora theridion n. gen, n. sp., infecting both Atlantic salmon (Salmo salar) and its copepod parasite Lepeophtheirus salmonis is described. The microsporidian exhibits nuclei in diplokaryotic arrangement during all known life-cycle stages in salmon, but only in the merogonal stages and early sporogonal stage in salmon lice. All developmental stages ...

The cell cycle is a highly regulated and fundamental cellular process that involves complex feedback regulation of many proteins, and any compromise to its integrity elicits dire consequences for the cell. For example, in neurodegenerative diseases such as Alzheimer disease (AD), evidence for abnormal cell cycle re-entry precedes other hallmarks ...

Coordination between cell fate specification and cell cycle control in multicellular organisms is essential to regulate cell numbers in tissues and organs during development, and its failure may lead to oncogenesis. In mammalian cells, as part of a general cell cycle checkpoint mechanism, the F-box protein beta-transducin repeat-containing protein (beta-TrCP) ...

SUMO, a reversible post-translational protein modifier, plays important roles in many processes of higher eukaryotic cell life. Although SUMO has been identified in many eukaryotes, SUMO and SUMO system are still unknown in some eukaryotic unicellular organisms, such as Trypanosoma brucei (T. brucei). In this study, only one SUMO homologue ...

The cell cycle consists of a number of complex biochemical pathways that ensure that the start of a particular event depends on the successful and right end of previous steps in the pathway. An important role is played by cyclin/cyclin-dependent kinase (cdk) complexes which are critical regulators of cell cycle ...

As a new class of xenogenous nanoparticle, quantum dots (QDs) possess the potential to co-exist with CU2+ in human liver. The combined toxicity is thus concerned. Considering QDs and Cu2+ are known ROS (reactive oxygen species) inducer, we investigated the combined oxidative stress and corresponding protective strategy using human hepatic ...

During embryonic development, cells are instructed which position to occupy, they interpret these cues as differentiation programmes, and expand these patterns by growth. Sonic hedgehog (Shh) specifies positional identity in many organs; however, its role in growth is not well understood. In this study, we show that inactivation of Shh ...

The complex neurodegeneration underlying Alzheimer disease (AD), although incompletely understood, is characterised by an aberrant re-entry into the cell cycle in neurons. Pathological evidence, in the form of cell cycle markers and regulatory proteins, suggests that cell cycle re-entry is an early event in AD, which precedes the formation of ...

Hematopoietic progenitors undergo differentiation while navigating several cell division cycles, but it is unknown whether these two processes are coupled. We addressed this question by studying erythropoiesis in mouse fetal liver in vivo. We found that the initial upregulation of cell surface CD71 identifies developmentally matched erythroblasts that are tightly ...

MS4a4B, a CD20 homologue in T cells, is a novel member of the MS4A gene family in mice. The MS4A family includes CD20, FcεRIβ, HTm4 and at least 26 novel members that are characterized by their structural features: with four membrane-spanning domains, two extracellular domains and two cytoplasmic regions. CD20, ...

Maintenance of genomic stability is needed for cells to survive many rounds of division throughout their lifetime. Key to the proper inheritance of intact genome is the tight temporal and spatial coordination of cell cycle events. Moreover, checkpoints are present that function to monitor the proper execution of cell cycle ...

Neurogenesis in the retina occurs via the coordination of proliferation, cell cycle exit and differentiation of retinal progenitor cells. Until recently, it was widely assumed that once a retinal progenitor cell produced a postmitotic neuron, there was no possibility for cell-cycle re-entry. However, recent studies have shown that mature differentiated ...

Many previous studies have attempted to gain insight into the underlying pathophysiology of schizophrenia by studying postmortem brain tissues of schizophrenia patients. However, such analyses can be confounded by artifactual features of this approach such as lengthy agonal state and postmortem interval times. As several aspects of schizophrenia are also ...

We investigated whether the anticancer drug Ukrain (UK) is able to modulate the expression of some of the key markers of tumor progression in pancreatic cell carcinoma, in order to assess its potential therapeutic effect. Three cell lines (HPAF-II, PL45, HPAC) were treated with UK (5, 10 and 20 μM) ...

p73, a recently described member of the p53 family of transcription factors, undergoes a number of posttranslational modifications, inducing cell cycle arrest and apoptosis. In the present study, we demonstrate that PIASy, a member of the PIAS SUMO-ligase family, interacts with p73alpha, and that PIASy-mediated sumoylation promotes proteasomal degradation of ...

Cellular division is an ordered, tightly regulated process involving multiple checkpoints that assess extracellular growth signals, cell size and DNA integrity. Progression throughout the cell cycle is based on the activation of different CDK-cyclin complexes that prevent cells from entering into a new phase until thay have successfully complete the ...

As model of organogenesis, the pituitary gland is a relatively simple tissue; yet, we understand little of the mechanisms that determine organ size, cell number and allocation of cells to different lineages. While the discovery of cell-restricted transcription factors has led to significant insight into the mechanisms controlling differentiation and ...

Recently, we have reported the initial characterization of a novel centrin from Dictyostelium discoideum (DdCenB).1 Sequence and phylogenetic analyses clearly establish DdCenB as a centrin, yet further characterization revealed some interesting peculiarities about this novel centrin. Figure 1 depicts the localization of DdCenB at three points in the cell cycle: ...

Human cells divide and proliferate during the early stages of life to support development, and throughout adult life to support normal cellular turnover. Each dividing cell follows an orderly and tightly regulated series of events known as the cell cycle. This process ensures proper cellular division that maintains DNA and ...

Sulforaphane (SFN), an isothiocyanate phytochemical present predominantly in cruciferous vegetables such as brussels sprout and broccoli, is considered a promising chemo-preventive agent against cancer. In-vitro exposure to SFN appears to result in the induction of apoptosis and cell-cycle arrest in a variety of tumor types. However, the molecular mechanisms leading ...

p107 and its related family members Rb and p130 are critical regulators of cellular proliferation and tumorigenesis. Due to the extent of functional overlap within the Rb family, it has been difficult to assess which functions are exclusive to individual members and which are shared. Like its family members, p107 ...

BACKGROUND: Because some of heat shock protein 90's (HSP90) clients are key cell cycle regulators, HSP90 inhibition can affect the cell cycle. Recently, celastrol is identified both as a novel inhibitor of HSP90 and as a potential anti-tumor agent. However, this agent's effects on the cell cycle are rarely investigated. ...

BACKGROUND: The control of the subcellular localization of cell cycle regulators has emerged as a crucial mechanism in cell division regulation. The active transport of proteins between the nucleus and the cytoplasm is mediated by the transport receptors of the beta-karyopherin family. In this work we characterized the terminal phenotype ...

17-Allylamino-17-demethoxygeldanamycin (17-AAG), a benzoquinone ansamycin antibiotic, specifically targets heat shock protein 90 (Hsp90) and interferes with its function as a molecular chaperone that maintains the structural and functional integrity of various protein clients involved in cellular signaling. In this study, we have investigated the effect of 17-AAG on the regulation ...

Mutations in the human gene coding for XPD lead to segmental progeria - the premature appearance of some of the phenotypes normally associated with aging - which may or may not be accompanied by increased cancer incidence. XPD is required for at least three different critical cellular functions: in addition ...

ABSTRACT: Regulation of cell cycle progression in changing environments is vital for cell survival and maintenance, and different regulation mechanisms based on cell size and cell cycle time have been proposed. To determine the mechanism of cell cycle regulation in the unicellular green algae Chlamydomonas reinhardtii, we developed an on-chip ...

The syndecan family consists of four distinct membrane glycoproteins in mammals. Syndecans control cell proliferation, differentiation, adhesion and migration through participation in cell-cell interactions, anchorage of cells to the extracellular environment, and modulation of multiple growth factors. Therefore, syndecans may play a pivotal role in the regulation of cell behaviour ...

The ubiquitin-based molecular switch dictating error free versus error prone repair has been conserved throughout eukaryotic evolution. A central component of this switch is the homotrimeric clamp PCNA, which is ubiquitinated in response to genotoxic stress allowing recovery of replication forks blocked at sites of DNA damage. The particulars of ...

Transcriptional and postranslational regulation of the cell cycle has been widely studied. However, there is scarce knowledge concerning translational control of this process. Several mammalian eukaryotic initiation factors (eIFs) seem to be implicated in controlling cell proliferation. In this work, we investigated if the human eIF3f expression and function is ...

Cdc20 is a highly conserved activator of the anaphase-promoting complex (APC), promoting cell-cycle-regulated ubiquitination and proteolysis of a number of critical cell-cycle-regulatory targets including securin and mitotic cyclins. APC-Cdc20 activity is tightly regulated, and this regulation is likely important for accurate cell cycle control. One significant component of Cdc20 regulation ...

The cyclin dependent kinase Cdk1 controls the cell cycle, which is best understood in the model organism S. cerevisiae. Research performed during the past decade has significantly improved our understanding of the molecular machinery of the cell cycle. Approximately 75 targets of Cdk1 have been identified that control critical cell ...

Mutations in SMARCAL1 cause Schimke Immuno-Osseous Dysplasia (SIOD), an autosomal recessive multisystem developmental disease characterized by growth retardation, T-cell deficiency, bone marrow failure, anemia and renal failure. SMARCAL1 encodes an ATP-driven annealing helicase. However, the biological function of SMARCAL1 and the molecular basis of SIOD remain largely unclear. In this ...

Bromodomain and Extra Terminal domain (BET) proteins are characterized by the presence of two types of domains, the bromodomain and the extra terminal domain. They bind to acetylated lysines present on histone tails and control gene transcription. They are also well known to play an important role in cell cycle ...

The F-box protein Fbxw7 (also known as Fbw7, SEL-10, hCdc4 or hAgo) mediates the ubiquitylation and thereby contributes to the degradation of proteins that positively regulate cell cycle. Conditional ablation of Fbxw7 in mouse embryonic fibroblasts (MEFs) induces cell-cycle arrest accompanied by abnormal accumulation of the intracellular domain of Notch1 ...

In the established model of mammalian cell cycle control, the retinoblastoma protein (Rb) functions to restrict cells from entering S phase by binding and sequestering E2f activators (E2f1, E2f2 and E2f3), which are invariably portrayed as the ultimate effectors of a transcriptional program that commit cells to enter and progress ...

Understanding of the cell cycle control logic in Caulobacter has progressed to the point where we now have an integrated view of the operation of an entire bacterial cell cycle system functioning as a state machine. Oscillating levels of a few temporally-controlled master regulator proteins in a cyclical circuit drive ...

Cellular adenosine accumulates under stress conditions. Few papers on adenosine are concerned with its function in the cell cycle. The cell cycle is the essential mechanism by which all living things reproduce and the target machinery when cells encounter stresses, so it is necessary to examine the relationship between adenosine ...

The actin severing protein cofilin is essential for directed cell migration and chemotaxis, in many cell types and is also important for tumor cell invasion during metastasis. Through its severing activity, cofilin increases the number of free barbed ends to initiate actin polymerization for actin-based protrusion in two distinct subcellular ...

The Rho associated coiled coil protein kinase (ROCK) dependent signaling pathway plays an important role in numerous physiological functions such as cell proliferation, adhesion, migration and inflammation. Human embryonic stem cells (hESCs) undergo differentiation and poor survival after single cell dissociation in culture thus limiting their expansion for cell based ...

Aloysia gratissima is used in Brazilian folk medicine for the treatment of digestive and respiratory diseases. The infusions (6 and 24 g L-1) and essential oils (0.25%, on ethanol) were prepared and we used groups of five Allium cepa bulbs for each treatment. A total of 2500 cells per treatment ...

The cellular oxidation and reduction (redox) environment is influenced by the production and removal of reactive oxygen species (ROS). In recent years, several reports support the hypothesis that cellular ROS levels could function as ''second messengers'' regulating numerous cellular processes, including proliferation. Periodic oscillations in the cellular redox environment, a ...

Spontaneous Ca(2+) events have been observed in diverse stem cell lines, including carcinoma and mesenchymal stem cells. Interestingly, during cell cycle progression, cells exhibit Ca(2+) transients during the G(1) to S transition, suggesting that these oscillations may play a role in cell cycle progression. We aimed to study the influence ...

The TP53 tumor suppressor gene is the most frequently inactivated gene in human cancer identified to date. However, TP53 mutations are rare in human mesotheliomas, as well as in many other types of cancer, suggesting that aberrant TP53 function may be due to alterations in its regulatory pathways. Mouse double ...

Bone formation and osteoblast differentiation require the functional expression of the Runx2/Cbfbeta heterodimeric transcription factor complex. Runx2 is also a suppressor of proliferation in osteoblasts by attenuating cell cycle progression in G(1). Runx2 levels are modulated during the cell cycle, which are maximal in G(1) and minimal beyond the G(1)/S ...

The ability of an animal, normally dependent on aerobic respiration, to suspend breathing and enter an anoxic state for long term survival is clearly a fascinating feat, and has been the focus of numerous biochemical studies. When anoxia tolerant turtles are faced with periods of oxygen deprivation, numerous physiological and ...