scholarly journals Feedback repression of polyamine transport is mediated by antizyme in mammalian tissue-culture cells

1994 ◽  
Vol 299 (1) ◽  
pp. 19-22 ◽  
Author(s):  
J L Mitchell ◽  
G G Judd ◽  
A Bareyal-Leyser ◽  
S Y Ling
Keyword(s):  
Ornithine Decarboxylase ◽  
Mammalian Cells ◽  
Feedback Inhibition ◽  
Mammalian Tissue ◽  
Polyamine Biosynthesis ◽  
Culture Cells ◽  
Tissue Culture Cells ◽  
Polyamine Transport ◽  
A Cell ◽  
Polyamine Uptake

Antizyme, a spermidine-induced protein that binds and stimulates ornithine decarboxylase degradation, is now shown also to mediate the rapid feedback inhibition of polyamine uptake into mammalian cells. Using a cell line (HZ7) transfected with truncated antizyme cDNA, and mutant ornithine decarboxylase cell lines, we demonstrate that this newly discovered action of antizyme is distinct from its role in modulating polyamine biosynthesis.

Inactivation of cdc2 kinase during mitosis requires regulated and constitutive proteins in a cell-free system

1993 ◽  
Vol 104 (3) ◽  
pp. 873-881
Author(s):  
F.A. Suprynowicz
Keyword(s):  
Mammalian Cells ◽  
Protein Phosphatase 1 ◽  
Cdc2 Kinase ◽  
Free System ◽  
Culture Cells ◽  
Anaphase Onset ◽  
Tissue Culture Cells ◽  
A Cell ◽  
Protein Components

Inactivation of the cyclin-p34cdc2 protein kinase complex is a major requirement for anaphase onset and exit from mitosis. To facilitate identification of specific molecules that regulate this event in mammalian cells, I have developed a cell-free assay in which cdc2 kinase associated with a chromosomal fraction from metaphase tissue culture cells is inactivated by a cell-cycle-regulated cytosolic system. In vitro kinase inactivation requires ATP, Mg2+ and the dephosphorylation of one or more sites in the chromosomal fraction by protein phosphatase 1 and/or 2A. Cyclin B is destroyed during inactivation, while the level of p34cdc2 remains constant. Ammonium sulfate fractionation resolves the cytosolic inactivating system into at least two distinct protein components that are both required for inactivation and are differentially regulated during mitosis.

scholarly journals ATP13A3 is a major component of the enigmatic mammalian polyamine transport system

2020 ◽  
pp. jbc.RA120.013908
Author(s):  
Norin Nabil Hamouda ◽  
Chris Van den Haute ◽  
Roeland Vanhoutte ◽  
Ragna Sannerud ◽  
Mujahid Azfar ◽  
...  
Keyword(s):  
Transport System ◽  
Mammalian Cells ◽  
Polyamine Biosynthesis ◽  
Polyamine Transport System ◽  
Polyamine Transport ◽  
Mrna And Protein Expression ◽  
Transport Inhibitors ◽  
Pulmonary Arterial ◽  
Polyamine Uptake ◽  
P Type

Polyamines, such as putrescine, spermidine and spermine, are physiologically important polycations, but the transporters responsible for their uptake in mammalian cells remain poorly characterized. Here, we reveal a new component of the mammalian polyamine transport system (PTS) using CHO-MG cells, a widely used model to study alternative polyamine uptake routes and characterize polyamine transport inhibitors for therapy. CHO-MG cells present polyamine uptake deficiency and resistance to a toxic polyamine biosynthesis inhibitor MGBG (methylglyoxal bis- (guanylhydrazone)), but the molecular defects responsible for these cellular characteristics remain unknown. By genome sequencing of CHO-MG cells, we identified mutations in an unexplored gene, ATP13A3, and found disturbed mRNA and protein expression. ATP13A3 encodes for an orphan P5B-ATPase (ATP13A3), a P-type transport ATPase that represents a candidate polyamine transporter. Interestingly, ATP13A3 complemented the putrescine transport deficiency and MGBG resistance of CHO-MG cells, whereas its knockdown in wild-type cells induced a CHO-MG phenotype, demonstrating a decrease in putrescine uptake and MGBG sensitivity. Taken together, our findings identify ATP13A3 as a major component of the mammalian PTS that confers sensitivity to MGBG and that has been previously genetically linked with pulmonary arterial hypertension.

Sulfhydryl bond formation is a prerequisite for proper cycling of centrosomes and chromosomes in mammalian tissue culture cells

1993 ◽  
Vol 51 ◽  
pp. 342-343
Author(s):  
Heide Schatten ◽  
Neidhard Paweletz ◽  
Ron Balczon
Keyword(s):  
Tissue Culture ◽  
Cell Cycle Progression ◽  
Group Formation ◽  
Sulfhydryl Group ◽  
Mammalian Tissue ◽  
Mitotic Chromosomes ◽  
Microtubule Network ◽  
Culture Cells ◽  
Tissue Culture Cells ◽  
Transmission Electron

To study the role of sulfhydryl group formation during cell cycle progression, mammalian tissue culture cells (PTK2) were exposed to 100¼M 2-mercaptoethanol for 2 to 6 h during their exponential phase of growth. The effects of 2-mercaptoethanol on centrosomes, chromosomes, microtubules, membranes and intermediate filaments were analyzed by transmission electron microscopy (TEM) and by immunofluorescence microscopy (IFM) methods using a human autoimmune antibody directed against centrosomes (SPJ), and a mouse monoclonal antibody directed against tubulin (E7). Chromosomes were affected most by this treatment: premature chromosome condensation was detected in interphase nuclei, and the structure in mitotic chromosomes was altered compared to control cells. This would support previous findings in dividing sea urchin cells in which chromosomes are arrested at metaphase while the centrosome splitting cycle continues. It might also support findings that certairt-sulfhydryl-blocking agents block cyclin destruction. The organization of the microtubule network was scattered probably due to a looser organization of centrosomal material at the interphase centers and at the mitotic poles.

scholarly journals Screens Using RNAi and cDNA Expression as Surrogates for Genetics in Mammalian Tissue Culture Cells

2005 ◽  
Vol 70 (0) ◽  
pp. 449-459 ◽  
Author(s):  
J. PEARLBERG ◽  
S. DEGOT ◽  
W. ENDEGE ◽  
J. PARK ◽  
J. DAVIES ◽  
...  
Keyword(s):  
Tissue Culture ◽  
Mammalian Tissue ◽  
Culture Cells ◽  
Tissue Culture Cells ◽  
Cdna Expression

scholarly journals Excess putrescine accumulation inhibits the formation of modified eukaryotic initiation factor 5A (eIF-5A) and induces apoptosis

1997 ◽  
Vol 328 (3) ◽  
pp. 847-854 ◽  
Author(s):  
E. Margaret TOME ◽  
M. Steven FISER ◽  
M. Claire PAYNE ◽  
W. Eugene GERNER
Keyword(s):  
Ornithine Decarboxylase ◽  
Competitive Inhibitor ◽  
Initiation Factor ◽  
Protective Mechanism ◽  
Eukaryotic Initiation Factor ◽  
Post Translational Modification ◽  
Resistant Variant ◽  
Culture Cells ◽  
Tissue Culture Cells

DH23A cells, an α-difluoromethylornithine-resistant variant of the parental hepatoma tissue culture cells, express high levels of stable ornithine decarboxylase. Aberrantly high expression of ornithine decarboxylase results in a large accumulation of endogenous putrescine and increased apoptosis in DH23A cells when α-difluoromethylornithine is removed from the culture. Treatment of DH23A cells with exogenous putrescine in the presence of α-difluoromethylornithine mimics the effect of drug removal, suggesting that putrescine is a causative agent or trigger of apoptosis. Accumulation of excess intracellular putrescine inhibits the formation of hypusine in vivo, a reaction that proceeds by the transfer of the butylamine moiety of spermidine to a lysine residue in eukaryotic initiation factor 5A (eIF-5A). Treatment of DH23A cells with diaminoheptane, a competitive inhibitor of the post-translational modification of eIF-5A, causes both the suppression of eIF-5A modification in vivo and induction of apoptosis. These data support the hypothesis that rapid degradation of ornithine decarboxylase is a protective mechanism to avoid cell toxicity from putrescine accumulation. Further, these data suggest that suppression of modified eIF-5A formation is one mechanism by which cells may be induced to undergo apoptosis.

Cytoplasmic inheritance in mammalian tissue culture cells

In Vitro ◽  
1976 ◽  
Vol 12 (11) ◽  
pp. 758-776 ◽  
Author(s):  
Douglas C. Wallace ◽  
Y. Pollack ◽  
C. L. Bunn ◽  
J. M. Eisenstadt
Keyword(s):  
Tissue Culture ◽  
Cytoplasmic Inheritance ◽  
Mammalian Tissue ◽  
Culture Cells ◽  
Tissue Culture Cells
Sign in / Sign up

Export Citation Format

Share Document