Friend erythroleukemia cell membrane transferrin receptors

1980 ◽  
Vol 58 (10) ◽  
pp. 935-940 ◽  
Author(s):  
A. Wilczynska ◽  
H. M. Schulman

We have compared the uptake of transferrin by murine Friend erythroleukemia cells with the uptake of transferrin by murine reticulocytes. Friend cells which had been induced to erythroid differentiation by dimethyl sulfoxide took up transferrin in a manner qualitatively and quantitatively similar to the uptake of transferrin by reticulocytes, while uninduced Friend cells took up only negligible amounts of transferrin. Specific transferrin-binding activity could be demonstrated in detergent extracts of membranes from induced cells and this activity was isolated from membrane extracts by the use of antibody to transferrin. The isolated membrane component(s) with transferrin-binding activity migrated electrophoretically as a single protein on sodium dodecyl sulfate gels and had similar properties to a transferrin-binding protein isolated previously from reticulocytes.

Blood ◽  
1977 ◽  
Vol 50 (5) ◽  
pp. 867-876 ◽  
Author(s):  
BP Alter ◽  
SC Goff

Abstract Friend erythroleukemia cells, originally derived from DBA/2 mice, differentiate when cultured with inducing agents. Studies of the different effects of inducing agents on clone 745 have revealed that both dimethyl sulfoxide (DMSO) and hemin produce benzidine-positive cells. Butyric acid produced mature but benzidine-negative cells in this clone. All agents induced globin synthesis above the 0.1% of protein synthesis found in uninduced cells. DMSO induction stimulated globin synthesis 9%, hemin 2%, and butyric acid 3%. Total beta/alpha ratios were approximately unity with all agents. Although the inducing agents all stimulated total globin synthesis in Friend cells, the relative rates of synthesis of the two mouse beta chains were affected differently by the various agents. Hemin markedly increased the proportion of beta minor. For example, DBA/2 mouse reticulocytes synthesized 20% beta minor and 80% beta major. DMSO induction of clone 745 caused 20%-33% synthesis of beta minor. In contrast, hemin increased the proportion of beta minor to 64%-69%. Thus the Friend erythroleukemia cell system provides an in vitro approach to the study of the regulation of globin-chain switching.


1982 ◽  
Vol 2 (8) ◽  
pp. 1020-1024 ◽  
Author(s):  
J A Bilello ◽  
K K Gauri ◽  
J Kühne ◽  
G Warnecke ◽  
G Koch

Alkyldeoxyuridines which differ from thymidine by a C5 substitution of straight or branched alkyl chains of two to six carbon atoms have been tested for their ability to be taken up, phosphorylated, and incorporated into DNA. Analysis of the uptake of 5-ethyl-2'-deoxyuridine and 5-propyl-2'-deoxyuridine (n-PrdU)--similar to both thymidine and 5-bromo-2'-deoxyuridine--indicates that transport is dependent upon a functional cellular thymidine kinase. All of the aforementioned pyrimidines with the exception of n-PrdU are phosphorylated to the triphosphate and incorporated into DNA. The homologs 5-iso-propyl-2'-deoxyuridine (iso-PrdU) and 5-hexyl-2'-deoxyuridine are neither transported into the cell, phosphorylated, nor incorporated into DNA. These analogs were tested (i) for their ability to induce in the absence of dimethyl sulfoxide and (ii) to determine whether they enhance or inhibit dimethyl sulfoxide-induced differentiation of Friend erythroleukemia cells. Inhibition of erythroid differentiation appears to require the incorporation of thymidine analogs into DNA, and thus only 5-ethyl-2'-deoxyuridine and 5-bromo-2'-deoxyuridine were effective in inhibiting dimethyl sulfoxide-induced differentiation. The observation that iso-PrdU, and to a lesser extent n-PrdU and 5-propyldeoxyuridine monophosphate, induce differentiation under conditions in which they are not detectable intracellularly is strong evidence that this class of inducer acts at the cell membrane.


1985 ◽  
Vol 5 (8) ◽  
pp. 1993-1996 ◽  
Author(s):  
A B Sachs ◽  
R D Kornberg

Polyadenylate-binding activity can be detected in eluates from sodium dodecyl sulfate gels by a nitrocellulose filter-binding assay. Nuclear extracts from rat liver show a single peak of binding activity at 50 to 55 kilodaltons; cytoplasmic extracts show a single peak at 70 to 80 kilodaltons, corresponding to a 75-kilodalton protein previously described. Similar results are obtained with yeast and mouse fibroblasts, indicating a high degree of conservation of both nuclear and cytoplasmic polyadenylate-binding proteins. The activity from rat liver nuclei has been purified 125-fold on the basis of specific binding to polyadenylate and shows two main bands in sodium dodecyl sulfate gels at 53 and 55 kilodaltons.


1988 ◽  
Vol 8 (10) ◽  
pp. 4270-4281
Author(s):  
C G Kim ◽  
K M Barnhart ◽  
M Sheffery

Three erythroid cell factors that bind the murine alpha-globin promoter were enriched more than 1,000-fold by conventional and DNA sequence affinity chromatography. Visualization of enriched polypeptides revealed simple patterns suggesting that each binding activity was purified. Two of the purified proteins, alpha-CP1 and alpha-CP2, have been shown previously to interact with distinct binding sites that overlap in the alpha-globin CCAAT box. Affinity purification of alpha-CP1 revealed seven polypeptides with Mrs raging from 27,000 to 38,000. In contrast, purified alpha-CP2 was made up of a polypeptide doublet with Mrs of 64,000 and 66,000. The third purified binding activity, alpha-IRP, interacted with sequences that formed an inverted repeat (IR) between the alpha-globin CCAAT and TATAA boxes. Affinity-purified alpha-IRP was made up of a single polypeptide with an Mr of 85,000. We confirmed that the purified polypeptides corresponded to alpha-CP1-, alpha-CP2-, and alpha-IRP-binding activities by UV cross-linking experiments (alpha-CP2 and alpha-IRP) or by renaturation of binding activity after elution of polypeptides from sodium dodecyl sulfate-polyacrylamide gels (alpha-CP1 and alpha-CP2). The apparent complexity of the polypeptides accounting for alpha-CP1 binding activity prompted a further physical characterization of this factor. Sedimentation of affinity-purified alpha-CP1 in glycerol gradients containing 100 mM KCl showed that all seven polypeptides migrated as a complex that cosedimented with alpha-CP1-binding activity. In contrast, when sedimented in glycerol gradients containing 500 mM KCl, alpha-CP1 dissociated into at least two components. Under these conditions, alpha-CP1-binding activity was reduced or lost. Activity was reconstituted, however, by combining fractions that were enriched in the two components. These results were confirmed by experiments in which we showed that alpha-CP1-binding activity can be recovered only by combining distinct sets of polypeptides that were isolated and renatured from sodium dodecyl sulfate-polyacrylamide gels. Our results suggest that the seven polypeptides visualized after affinity purification of alpha-CP1 interact to form a heterotypic complex (or set of complexes) required for alpha-CP1-binding activity.


1985 ◽  
Vol 5 (8) ◽  
pp. 1993-1996
Author(s):  
A B Sachs ◽  
R D Kornberg

Polyadenylate-binding activity can be detected in eluates from sodium dodecyl sulfate gels by a nitrocellulose filter-binding assay. Nuclear extracts from rat liver show a single peak of binding activity at 50 to 55 kilodaltons; cytoplasmic extracts show a single peak at 70 to 80 kilodaltons, corresponding to a 75-kilodalton protein previously described. Similar results are obtained with yeast and mouse fibroblasts, indicating a high degree of conservation of both nuclear and cytoplasmic polyadenylate-binding proteins. The activity from rat liver nuclei has been purified 125-fold on the basis of specific binding to polyadenylate and shows two main bands in sodium dodecyl sulfate gels at 53 and 55 kilodaltons.


1974 ◽  
Vol 52 (11) ◽  
pp. 1003-1012 ◽  
Author(s):  
D. J. Bailey ◽  
R. K. Murray ◽  
F. S. Rolleston

The proteins of rough and smooth endoplasmic reticulum of rat liver were examined by electrophoresis in (1) a starch – urea – aluminum lactate system, which resolved 10 components; (2) a starch – urea – aluminum lactate – mercaptoethanol system which resolved 18 components; and (3) a polyacrylamide – sodium dodecyl sulfate (SDS) – urea – mercaptoethanol system, which resolved 33–34 components. In each system, the protein patterns of the membranes of the rough and smooth endoplasmic reticulum were found to be very similar. However, using polyacrylamide–SDS the rough endoplasmic reticulum was found to contain a protein of molecular weight 36 000, which was barely detectable in the smooth endoplasmic reticulum. Evidence is presented which suggests that this was a membrane component, although the possibility that it was a ribosomal protein could not be absolutely excluded. The membranes of the endoplasmic reticulum of male rats were also found to contain a protein of molecular weight 35 000, which was barely detectable in membranes from female rats.


2021 ◽  
Vol 28 (1) ◽  
Author(s):  
Christos I. Papagiannopoulos ◽  
Nikoleta F. Theodoroula ◽  
Konstantinos A. Kyritsis ◽  
Melpomeni G. Akrivou ◽  
Maria Kosmidou ◽  
...  

Abstract Background Erythroleukemia is caused by the uncontrolled multiplication of immature erythroid progenitor cells which fail to differentiate into erythrocytes. By directly targeting this class of malignant cells, the induction of terminal erythroid differentiation represents a vital therapeutic strategy for this disease. Erythroid differentiation involves the execution of a well-orchestrated gene expression program in which epigenetic enzymes play critical roles. In order to identify novel epigenetic mediators of differentiation, this study explores the effects of multiple, highly specific, epigenetic enzyme inhibitors, in murine and human erythroleukemia cell lines. Results We used a group of compounds designed to uniquely target the following epigenetic enzymes: G9a/GLP, EZH1/2, SMYD2, PRMT3, WDR5, SETD7, SUV420H1 and DOT1L. The majority of the probes had a negative impact on both cell proliferation and differentiation. On the contrary, one of the compounds, A-366, demonstrated the opposite effect by promoting erythroid differentiation of both cell models. A-366 is a selective inhibitor of the G9a methyltransferase and the chromatin reader Spindlin1. Investigation of the molecular mechanism of action revealed that A-366 forced cells to exit from the cell cycle, a fact that favored erythroid differentiation. Further analysis led to the identification of a group of genes that mediate the A-366 effects and include CDK2, CDK4 and CDK6. Conclusions A-366, a selective inhibitor of G9a and Spindlin1, demonstrates a compelling role in the erythroid maturation process by promoting differentiation, a fact that is highly beneficial for patients suffering from erythroleukemia. In conclusion, this data calls for further investigation towards the delivery of epigenetic drugs and especially A-366 in hematopoietic disorders.


1982 ◽  
Vol 2 (8) ◽  
pp. 1020-1024
Author(s):  
J A Bilello ◽  
K K Gauri ◽  
J Kühne ◽  
G Warnecke ◽  
G Koch

Alkyldeoxyuridines which differ from thymidine by a C5 substitution of straight or branched alkyl chains of two to six carbon atoms have been tested for their ability to be taken up, phosphorylated, and incorporated into DNA. Analysis of the uptake of 5-ethyl-2'-deoxyuridine and 5-propyl-2'-deoxyuridine (n-PrdU)--similar to both thymidine and 5-bromo-2'-deoxyuridine--indicates that transport is dependent upon a functional cellular thymidine kinase. All of the aforementioned pyrimidines with the exception of n-PrdU are phosphorylated to the triphosphate and incorporated into DNA. The homologs 5-iso-propyl-2'-deoxyuridine (iso-PrdU) and 5-hexyl-2'-deoxyuridine are neither transported into the cell, phosphorylated, nor incorporated into DNA. These analogs were tested (i) for their ability to induce in the absence of dimethyl sulfoxide and (ii) to determine whether they enhance or inhibit dimethyl sulfoxide-induced differentiation of Friend erythroleukemia cells. Inhibition of erythroid differentiation appears to require the incorporation of thymidine analogs into DNA, and thus only 5-ethyl-2'-deoxyuridine and 5-bromo-2'-deoxyuridine were effective in inhibiting dimethyl sulfoxide-induced differentiation. The observation that iso-PrdU, and to a lesser extent n-PrdU and 5-propyldeoxyuridine monophosphate, induce differentiation under conditions in which they are not detectable intracellularly is strong evidence that this class of inducer acts at the cell membrane.


2005 ◽  
Vol 79 (20) ◽  
pp. 12752-12762 ◽  
Author(s):  
Kazuo Nishigaki ◽  
Charlotte Hanson ◽  
Delores Thompson ◽  
Takashi Yugawa ◽  
Sandra Ruscetti

ABSTRACT Members of the mitogen-activated protein kinase (MAPK) family, including Jun amino-terminal kinase (JNK) and extracellular signal-related kinase (ERK), play an important role in the proliferation of erythroid cells in response to erythropoietin (Epo). Erythroid cells infected with the Friend spleen focus-forming virus (SFFV) proliferate in the absence of Epo and show constitutive activation of Epo signal transduction pathways. We previously demonstrated that the ERK pathway was constitutively activated in Friend SFFV-infected erythroid cells, and in this study JNK is also shown to be constitutively activated. Pharmacological inhibitors of both the ERK and JNK pathways stopped the proliferation of primary erythroleukemic cells from Friend SFFV-infected mice, with little induction of apoptosis, and furthermore blocked their ability to form Epo-independent colonies. However, only the JNK inhibitor blocked the proliferation of erythroleukemia cell lines derived from these mice. The JNK inhibitor caused significant apoptosis in these cell lines as well as an increase in the fraction of cells in G2/M and undergoing endoreduplication. In contrast, the growth of erythroleukemia cell lines derived from Friend murine leukemia virus (MuLV)-infected mice was inhibited by both the MEK and JNK inhibitors. JNK is important for AP1 activity, and we found that JNK inhibitor treatment reduced AP1 DNA-binding activity in primary erythroleukemic splenocytes from Friend SFFV-infected mice and in erythroleukemia cell lines from Friend MuLV-infected mice but did not alter AP1 DNA binding in erythroleukemia cell lines from Friend SFFV-infected mice. These data suggest that JNK plays an important role in cell proliferation and/or the survival of erythroleukemia cells.


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