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Glycine decarboxylase activity drives non-small cell lung cancer tumor-initiating cells and tumorigenesis

Identification of the factors critical to the tumor-initiating cell (TIC) state may open new avenues in cancer therapy. Here we show that the metabolic enzyme glycine decarboxylase (GLDC) is critical for TICs in non-small cell lung cancer (NSCLC). TICs from primary NSCLC tumors express high levels of the oncogenic stem cell factor LIN28B and GLDC, which are both required for TIC growth and tumorig

Genetic mouse models to investigate cell cycle regulation

Early studies on cell cycle regulation were based on experiments in model systems (Yeast, Xenopus, Starfish, Drosophila) and have shaped the way we understand many events that control the cell cycle. Although these model systems are of great value, the last decade was highlighted by studies done in human cells and using in vivo mouse models. Mouse models are irreplaceable tools for understanding t

CDK2 is dispensable for adult hippocampal neurogenesis

Granule neurons of the dentate gyrus (DG) of the hippocampus undergo continuous renewal throughout life. Among cell cycle regulators, cyclin-dependent kinase 2 (Cdk2) is considered as a major regulator of S-phase entry. We used Cdk2-deficient mice to decipher the requirement of Cdk2 for the generation of new neurons in the adult hippocampus. The quantification of cell cycle markers first revealed

p27kip1 (cyclin-dependent kinase inhibitor 1B) controls ovarian development by suppressing follicle endowment and activation and promoting follicle atresia in mice

In humans, the molecular mechanisms underlying ovarian follicle endowment and activation, which are closely related to the control of female reproduction, occurrence of menopause, and related diseases such as premature ovarian failure, are poorly understood. In the current study, we provide several lines of genetic evidence that the cyclin-dependent kinase (Cdk) inhibitor 1B (commonly known as p27

CDK2 is required by MYC to induce apoptosis

Depending upon the cellular and physiologic context, the overexpression of the MYC proto-oncogene results in rapid cell growth, proliferation, induction of apoptosis and/or proliferative arrest. What determines the precise consequences upon MYC activation is not clear. We have found that cyclin-dependent kinase 2 (CDK2) is required by MYC to induce apoptosis. MYC-induced apoptosis was suppressed i

Combined loss of Cdk2 and Cdk4 results in embryonic lethality and Rb hypophosphorylation

Mouse knockouts of Cdk2 and Cdk4 have demonstrated that, individually, these genes are not essential for viability. To investigate whether there is functional redundancy, we have generated double knockout (DKO) mice. Cdk2-/-Cdk4-/- DKOs die during embryogenesis around E15 as a result of heart defects. We observed a gradual decrease of Retinoblastoma protein (Rb) phosphorylation and reduced express

p205, A potential tumor suppressor, inhibits cell proliferation via multiple pathways of cell cycle regulation

p205 is a member of the interferon-inducible p200 family of proteins that regulate cell proliferation. Over-expression of p205 inhibits cell growth, although its mechanism of action is currently unknown. Therefore, we evaluated the effect of p205 on the p53 and Rb-dependent pathways of cell cycle regulation. p205 expression results in elevated levels of p21, and activates the p21 promoter in vitro

Cdk2 knockout mice are viable

Background: Cyclin-dependent kinases (Cdks) and their cyclin regulatory subunits control cell growth and division. Cdk2/cyclin E complexes are thought to be required because they phosphorylate the retinoblastoma protein and drive cells through the G1/S transition into the S phase of the cell cycle. In addition, Cdk2 associates with cyclin A, which itself is essential for cell proliferation during

CAK1 promotes meiosis and spore formation in Saccharomyces cerevisiae in a CDC28-independent fashion

CAK1 encodes a protein kinase in Saccharomyces cerevisiae whose sole essential mitotic role is to activate the Cdc28p cyclin-dependent kinase by phosphorylation of threonine-169 in its activation loop. SMK1 encodes a sporulation-specific mitogen-activated protein (MAP) kinase homolog that is required to regulate the postmeiotic events of spore wall assembly. CAK1 was previously identified as a mul

Kinetic analysis of the cyclin-dependent kinase-activating kinase (Cak1p) from budding yeast

Cak1p, the Cyclin-dependent kinase-activating kinase from budding yeast, is an unusual protein kinase that lacks many of the highly conserved motifs observed among members of the protein kinase superfamily. Cak1p phosphorylates and activates Cdc28p, the major cyclin-dependent kinase (CDK) in yeast, and is thereby required for passage through the yeast cell cycle. In this paper, we explore the kine

Dephosphorylation of human cyclin-dependent kinases by protein phosphatase type 2Cα and β2 isoforms

We previously reported that the activating phosphorylation on cyclin-dependent kinases in yeast (Cdc28p) and in humans (Cdk2) is removed by type 2C protein phosphatases. In this study, we characterize this PP2C-like activity ha HeLa cell extract and determine that it is due to PP2Cβ2, a novel PP2Cβ isoform, and to PP2Cα. PP2Cα and PP2Cβ2 co-purified with Mg2+-dependent Cdk2/Cdk6 phosphatase activi

Activating phosphorylation of the Kin28p subunit of yeast TFIIH by Cak1p

Cyclin-dependent kinase (CDK)-activating kinases (CAKs) carry out essential activating phosphorylations of CDKs such as Cdc2 and Cdk2. The catalytic subunit of mammalian CAK, MO15/Cdk7, also functions as a subunit of the general transcription factor TFIIH. However, these functions are split in budding yeast, where Kin28p functions as the kinase subunit of TFIIH and Cak1p functions as a CAK. We sho

‘Hot Spots’ of creatine kinase localization in brain : Cerebellum, hippocampus and choroid plexus

Creatine kinase (CK) isoenzymes, with emphasis on the mitochondrial CK isoenzymes, were characterized and localized in chicken cerebellum. Chicken cerebellar extracts analyzed by two-dimensional gels, using anti-peptide antibodies specific for sarcomeric muscle-type mitochondrial CK (Mib-CK) and revealed the presence of a Mib-CK variant in avian cerebellum. This CK isoform was localized by immunof

Identification of two distinctly localized mitochondrial creatine kinase isoenzymes in spermatozoa

The creatine kinase (CK) isoenzyme system is essential for motility in rooster and sea urchin sperm. In the present study, biochemical characterization as well as immunofluorescence and confocal laser microscopy with highly specific antibodies against various chicken CK isoenzymes revealed that cytosolic brain-type CK isoenzyme (B-CK) is the only CK isoenzyme in rooster seminal plasma, while three

In vitro complex formation between the octamer of mitochondrial creatine kinase and porin

An interaction of mitochondrial creatine kinase with purified outer mitochondrial porin (voltage-dependent anion channel) was shown by co- sedimentation assays as well as by gel permeation chromatography. Porin formed high M(r) complexes with wild-type mitochondrial creatine kinase as well as with an N-terminal deletion mutant, lacking the first five N-terminal amino acids. The complexes were iden

The N-terminal heptapeptide of mitochondrial creatine kinase is important for octamerization

Mitochondrial creatine kinase (Mi-CK) isoenzymes, in contrast to cytosolic CKs, form octameric molecules composed of four stable dimers. Octamers and dimers are interconvertible. Removal of the N-terminal pentapeptide of chicken cardiac Mi-CK (Mib-CK) by limited proteolysis drastically destabilized the octamer. The role of the charged amino acids within the N-terminal heptapeptide was studied in d

Outcome after heart-lung or lung transplantation in patients with Eisenmenger syndrome

Objective: The optimal timing for transplantation is unclear in patients with Eisenmenger syndrome (ES). We investigated post-transplantation survival and transplantation-specific morbidity after heart-lung transplantation (HLTx) or lung transplantation (LTx) in a cohort of Nordic patients with ES to aid decision-making for scheduling transplantation. Methods: We performed a retrospective, descrip

Ekonomisk politik. En vänbok till Assar Lindbeck

Enligt svensk akademisk tradition uppvaktades Assar Lindbeck med en vänbok när han lämnade chefskapet för Institutet för internationell ekonomi. Lars Jonung anmäler här festskriften. Han belyser bl a Lindbecks roll som framgångsrik akademisk entreprenör och diskuterar institutets funktion som plantskola och förebild för en generation av svenska nationalekonomer.

Substrate switches, phenotypic innovations and allopatric speciation formed taxonomic diversity within the lichen genus Blastenia

Blastenia is a widely distributed lichen genus in Teloschistaceae. We reconstructed its phylogeny in order to test species delimitation and to find evolutionary drivers forming recent Blastenia diversity. The origin of Blastenia is dated to the early Tertiary period, but later diversification events are distinctly younger. We recognized 24 species (plus 2 subspecies) within 6 infrageneric groups.