scholarly journals Biosynthesis of calmodulin in normal and virus-transformed chicken embryo fibroblasts.

1984 ◽  
Vol 4 (5) ◽  
pp. 883-889 ◽  
Author(s):  
J G Zendegui ◽  
R E Zielinski ◽  
D M Watterson ◽  
L J Van Eldik
Keyword(s):  
Chicken Embryo ◽  
Chicken Embryo Fibroblast ◽  
Cdna Probe ◽  
Transformed Cells ◽  
Synthesis Rate ◽  
Oncogenic Viruses ◽  
Transformed Fibroblasts ◽  
Significant Difference ◽  
Embryo Fibroblasts ◽  
Chicken Embryo Fibroblasts

We report here that the higher levels of calmodulin in transformed chicken embryo fibroblasts are due to an increase in the rate of synthesis of calmodulin that results from an increased amount of calmodulin-specific mRNA in transformed cells. Transformation of several types of eucaryotic cells by oncogenic viruses results in a two- to threefold increase in the intracellular levels of calmodulin. We used the normal chicken embryo fibroblast and its Rous sarcoma virus-transformed counterpart to examine the biosynthesis of calmodulin. We show that the higher levels of calmodulin found in transformed fibroblasts appear to be the consequence of a selective increase in the rate of synthesis of calmodulin above that of total soluble or total cellular protein. A significant difference in the rate of degradation of calmodulin or total protein between transformed and normal cells was not detected. We also examined the mechanism of the increased synthesis rate of calmodulin and show that the levels of calmodulin mRNA are increased in transformed fibroblasts as measured by both translational activity and hybridization to a calmodulin cDNA probe. It is suggested by these data that the higher levels of calmodulin in transformed cells may result from a specific increase in the rate of either calmodulin gene transcription or mRNA processing.

Biosynthesis of calmodulin in normal and virus-transformed chicken embryo fibroblasts

1984 ◽  
Vol 4 (5) ◽  
pp. 883-889
Author(s):  
J G Zendegui ◽  
R E Zielinski ◽  
D M Watterson ◽  
L J Van Eldik
Keyword(s):  
Chicken Embryo ◽  
Chicken Embryo Fibroblast ◽  
Cdna Probe ◽  
Transformed Cells ◽  
Synthesis Rate ◽  
Oncogenic Viruses ◽  
Transformed Fibroblasts ◽  
Significant Difference ◽  
Embryo Fibroblasts ◽  
Chicken Embryo Fibroblasts

We report here that the higher levels of calmodulin in transformed chicken embryo fibroblasts are due to an increase in the rate of synthesis of calmodulin that results from an increased amount of calmodulin-specific mRNA in transformed cells. Transformation of several types of eucaryotic cells by oncogenic viruses results in a two- to threefold increase in the intracellular levels of calmodulin. We used the normal chicken embryo fibroblast and its Rous sarcoma virus-transformed counterpart to examine the biosynthesis of calmodulin. We show that the higher levels of calmodulin found in transformed fibroblasts appear to be the consequence of a selective increase in the rate of synthesis of calmodulin above that of total soluble or total cellular protein. A significant difference in the rate of degradation of calmodulin or total protein between transformed and normal cells was not detected. We also examined the mechanism of the increased synthesis rate of calmodulin and show that the levels of calmodulin mRNA are increased in transformed fibroblasts as measured by both translational activity and hybridization to a calmodulin cDNA probe. It is suggested by these data that the higher levels of calmodulin in transformed cells may result from a specific increase in the rate of either calmodulin gene transcription or mRNA processing.

scholarly journals Tropomyosin isoforms in chicken embryo fibroblasts: purification, characterization, and changes in Rous sarcoma virus-transformed cells.

1985 ◽  
Vol 100 (3) ◽  
pp. 692-703 ◽  
Author(s):  
J J Lin ◽  
D M Helfman ◽  
S H Hughes ◽  
C S Chou
Keyword(s):  
Rous Sarcoma Virus ◽  
Chicken Embryo ◽  
Actin Binding ◽  
Transformed Cells ◽  
Two Dimensional ◽  
Tropomyosin Isoforms ◽  
Rous Sarcoma ◽  
Sarcoma Virus ◽  
Embryo Fibroblasts ◽  
Chicken Embryo Fibroblasts

Seven polypeptides (a, b, c, 1, 2, 3a, and 3b) have been previously identified as tropomyosin isoforms in chicken embryo fibroblasts (CEF) (Lin, J. J.-C., Matsumura, F., and Yamashiro-Matsumura, S., 1984, J. Cell. Biol., 98:116-127). Spots a and c had identical mobility on two-dimensional gels with the slow-migrating and fast-migrating components, respectively, of chicken gizzard tropomyosin. However, the remaining isoforms of CEF tropomyosin were distinct from chicken skeletal and cardiac tropomyosins on two-dimensional gels. The mixture of CEF tropomyosin has been isolated by the combination of Triton/glycerol extraction of monolayer cells, heat treatment, and ammonium sulfate fractionation. The yield of tropomyosin was estimated to be 1.4% of total CEF proteins. The identical set of tropomyosin isoforms could be found in the antitropomyosin immunoprecipitates after the cell-free translation products of total poly(A)+ RNAs isolated from CEF cells. This suggested that at least seven mRNAs coding for these tropomyosin isoforms existed in the cell. Purified tropomyosins (particularly 1, 2, and 3) showed different actin-binding abilities in the presence of 100 mM KCl and no divalent cation. Under this condition, the binding of tropomyosin 3 (3a + 3b) to actin filaments was significantly weaker than that of tropomyosin 1 or 2. CEF tropomyosin 1, and probably 3, could be cross-linked to form homodimers by treatment with 5,5'-dithiobis-(2-nitrobenzoate), whereas tropomyosin a and c formed a heterodimer. These dimer species may reflect the in vivo assembly of tropomyosin isoforms, since dimer formation occurred not only with purified tropomyosin but also with microfilament-associated tropomyosin. The expression of these tropomyosin isoforms in Rous sarcoma virus-transformed CEF cells has also been investigated. In agreement with the previous report by Hendricks and Weintraub (Proc. Natl. Acad. Sci. USA., 78:5633-5637), we found that major tropomyosin 1 was greatly reduced in transformed cells. We have also found that the relative amounts of tropomyosin 3a and 3b were increased in both the total cell lysate and the microfilament fraction of transformed cells. Because of the different actin-binding properties observed for CEF tropomyosins, changes in the expression of these isoforms may, in part, be responsible for the reduction of actin cables and the alteration of cell shape found in transformed cells.

Plasminogen activator: analysis of enzyme induction by ultraviolet irradiation mapping

1981 ◽  
Vol 1 (10) ◽  
pp. 884-890
Author(s):  
R Miskin ◽  
E Reich ◽  
K Dixon
Keyword(s):  
Plasminogen Activator ◽  
Cross Sections ◽  
Ultraviolet Irradiation ◽  
Chicken Embryo ◽  
Phorbol Esters ◽  
Transformed Cells ◽  
Normal Cells ◽  
Embryo Fibroblasts ◽  
Mapping Techniques ◽  
Chicken Embryo Fibroblasts

Ultraviolet irradiation mapping techniques have previously been used to study the organization of eucaryotic gene classes and transcription units. We used the same method to probe some regulatory phenomena observed in the induction of plasminogen activator (PA) biosynthesis: PA synthesis in chicken embryo fibroblasts is induced by tumor-promoting phorbol esters and by retinoic acid; furthermore, PA induction by phorbol esters is synergistic with transformation, being 10- to 20-fold greater in virus-transformed cells than in normal cells. We found that the ultraviolet irradiation inactivation cross sections for PA induction by phorbol esters and by retinoate differed significantly, suggesting that these agents induce PA biosynthesis by different mechanisms. On the other hand, the ultraviolet irradiation sensitivity of phorbol ester induction in normal chicken embryo fibroblasts was the same as in transformed cells, indicating that the synergism of transformation and phorbol esters is probably not due to different pathways of PA induction.

scholarly journals Identification of Phosphotyrosine-Containing Proteins in Untransformed and Rous Sarcoma Virus-Transformed Chicken Embryo Fibroblasts

1982 ◽  
Vol 2 (6) ◽  
pp. 653-665 ◽  
Author(s):  
Ricardo Martinez ◽  
Kenji D. Nakamura ◽  
Michael J. Weber
Keyword(s):  
Protein Kinases ◽  
Rous Sarcoma Virus ◽  
Chicken Embryo ◽  
Cellular Protein ◽  
Transformed Cells ◽  
Phosphoamino Acid ◽  
Rous Sarcoma ◽  
Sarcoma Virus ◽  
Embryo Fibroblasts ◽  
Chicken Embryo Fibroblasts

Phosphorylation on tyrosine residues mediated by pp60srcappears to be a primary biochemical event leading to the establishment of the transformed phenotype in Rous sarcoma virus (RSV)-infected cells. To identify the cellular proteins that undergo tyrosine phosphorylation during transformation, a32P-labeled RSV-transformed chicken embryo cell extract was analyzed by electrophoresis on a polyacrylamide gel. After slicing the gel into approximately 60 slices, phosphoamino acid analyses were carried out on the protein recovered from each gel slice. Phosphotyrosine was found in every gel slice, with two major peaks of this phosphoamino acid aroundMr's of 59 and 36 kilodaltons. When the same analysis was performed with cells infected with a transformation-defectivesrcdeletion mutant of RSV (tdNY101), significant and reproducible peaks of phosphotyrosine were found in only 2 of 60 gel slices. These gel slices corresponded toMr's of 42 and 40 kilodaltons. Identical results were obtained with normal uninfected chicken embryo fibroblasts. We conclude from these observations that pp60srcor the combined action of pp60srcand pp60src-activated cellular protein kinases cause the tyrosine-specific phosphorylation of a very large number of cellular polypeptides in RSV-transformed cells. In addition, untransformed cells appear to possess one or more active tyrosine-specific protein kinases which are responsible for the phosphorylation of a limited number of proteins. These proteins are different from the major phosphotyrosine-containing proteins of the transformed cells.

scholarly journals Two distinct enzymes contribute to biphasic S6 phosphorylation in serum-stimulated chicken embryo fibroblasts.

1990 ◽  
Vol 10 (6) ◽  
pp. 2787-2792 ◽  
Author(s):  
L J Sweet ◽  
D A Alcorta ◽  
R L Erikson
Keyword(s):  
Chicken Embryo ◽  
Kinase Activity ◽  
Chicken Embryo Fibroblast ◽  
Total Serum ◽  
S6 Kinase ◽  
Serum Stimulation ◽  
Ribosomal Protein S6 ◽  
Phosphopeptide Analysis ◽  
Embryo Fibroblasts ◽  
Chicken Embryo Fibroblasts

Serum stimulation of quiescent chicken embryo fibroblasts resulted in a time-dependent, biphasic activation of S6 kinase activity. Chromatographic fractionation of serum-stimulated cell lysates resolved two distinct S6 kinase activities. Anti-Xenopus S6 kinase II antiserum immunoprecipitated a 90,000-Mr S6 kinase but did not cross-react with a smaller, 65,000-Mr S6 kinase. Phosphopeptide analysis confirmed that the 90,000- and 65,000-Mr proteins were structurally unrelated and established that the 65,000-Mr protein isolated by the current protocol was the same serum-stimulated chicken embryo fibroblast S6 kinase as that previously characterized (J. Blenis, C. J. Kuo, and R. L. Erikson, J. Biol. Chem. 262:14373-14376, 1987). These results demonstrate the contribution of two distinct S6 kinases to total serum-stimulated ribosomal protein S6 phosphorylation.

Two distinct enzymes contribute to biphasic S6 phosphorylation in serum-stimulated chicken embryo fibroblasts

1990 ◽  
Vol 10 (6) ◽  
pp. 2787-2792
Author(s):  
L J Sweet ◽  
D A Alcorta ◽  
R L Erikson
Keyword(s):  
Chicken Embryo ◽  
Kinase Activity ◽  
Chicken Embryo Fibroblast ◽  
Total Serum ◽  
S6 Kinase ◽  
Serum Stimulation ◽  
Ribosomal Protein S6 ◽  
Phosphopeptide Analysis ◽  
Embryo Fibroblasts ◽  
Chicken Embryo Fibroblasts

Serum stimulation of quiescent chicken embryo fibroblasts resulted in a time-dependent, biphasic activation of S6 kinase activity. Chromatographic fractionation of serum-stimulated cell lysates resolved two distinct S6 kinase activities. Anti-Xenopus S6 kinase II antiserum immunoprecipitated a 90,000-Mr S6 kinase but did not cross-react with a smaller, 65,000-Mr S6 kinase. Phosphopeptide analysis confirmed that the 90,000- and 65,000-Mr proteins were structurally unrelated and established that the 65,000-Mr protein isolated by the current protocol was the same serum-stimulated chicken embryo fibroblast S6 kinase as that previously characterized (J. Blenis, C. J. Kuo, and R. L. Erikson, J. Biol. Chem. 262:14373-14376, 1987). These results demonstrate the contribution of two distinct S6 kinases to total serum-stimulated ribosomal protein S6 phosphorylation.

scholarly journals Polyacrylamide gel mapping of chicken tRNA: comparison of polysome-bound and whole-cell tRNA from normal and avian sarcoma virus-infected chicken embryo fibroblasts.

1982 ◽  
Vol 2 (10) ◽  
pp. 1247-1257 ◽  
Author(s):  
F Reinisch ◽  
T Heyman
Keyword(s):  
Chicken Embryo ◽  
Polyacrylamide Gel ◽  
Individual Species ◽  
Infected Chicken ◽  
Whole Cell ◽  
Significant Difference ◽  
Trna Species ◽  
Sarcoma Virus ◽  
Embryo Fibroblasts ◽  
Chicken Embryo Fibroblasts

Analysis of the tRNA population from chicken cells was performed by means of polyacrylamide gel mapping. About 60 species were detected; most of these were positively identified by their acceptor specificity. The comparison of polysome-bound and overall cellular tRNA gel patterns from normal and Rous sarcoma virus-infected chicken embryo fibroblasts led us to the following observations: some tRNA species were present in the same relative proportions in all the preparations, and within isoaccepting groups the same species was preponderant; however, although about 8% of whole-cell tRNA was recovered in polysomal preparations, amounts ranging from 3 to 30% were found for individual tRNA species. This points to the absence of a direct correlation between the amount of each mature tRNA species produced and the frequency with which it is used in this case of embryonic cells. No significant difference was observed between the whole-cell tRNA patterns from normal and infected cells. Thus, tRNA transcription appears unaltered when cells are transformed and virus producing. No change was observed in the extent of a post-transcriptional modification of tRNAPhe (the base Y). However, viral infection led to some changes in the relative proportions of individual species from polysomal preparations.

scholarly journals Effect of Fowl Adenovirus (FAdV-7) Infection on the Replication of Turkey Herpesvirus FC126 in Chicken Embryo Fibroblast Cultures

2012 ◽  
Vol 56 (4) ◽  
pp. 441-446 ◽  
Author(s):  
Jowita Samanta Niczyporuk ◽  
Grzegorz Woźniakowski ◽  
Elżbieta Samorek-Salamonowicz ◽  
Hanna Czekaj
Keyword(s):  
Chicken Embryo ◽  
Chicken Embryo Fibroblast ◽  
Field Strain ◽  
Fibroblast Cultures ◽  
Fowl Adenovirus ◽  
Simultaneous Infection ◽  
Embryo Fibroblasts ◽  
Different Doses ◽  
Chicken Embryo Fibroblasts

Abstract The aim of the study was to determine the influence of simultaneous infection of chicken embryo fibroblasts (CEF) with different doses of adenovirus field strain serotype 7 (FAdV-7 JN-5/10j) and turkey herpesvirus strain FC126 (FC126 HVT) on replication of the herpesvirus in in vitro cultures. Three experiments were performed: simultaneous infection of CEF with adenovirus and HVT; inoculation of CEF culture with adenovirus, followed by infection with HVT after 24 h; and inoculation of CEF with HVT, followed by the infection with adenovirus 24 h later. In order to detect the presence of HVT and adenovirus strains in CEF culture, SORF 1 and hexon genes were determined, respectively. The infection with adenovirus lowered replication of FC126 HVT in chicken embryo fibroblast.

Identification of mitogen-responsive ribosomal protein S6 kinase pp90rsk, a homolog of Xenopus S6 kinase II, in chicken embryo fibroblasts

1990 ◽  
Vol 10 (5) ◽  
pp. 2413-2417
Author(s):  
L J Sweet ◽  
D A Alcorta ◽  
S W Jones ◽  
E Erikson ◽  
R L Erikson
Keyword(s):  
Ribosomal Protein ◽  
Immune Complex ◽  
Chicken Embryo ◽  
Chicken Embryo Fibroblast ◽  
S6 Kinase ◽  
Ribosomal Protein S6 ◽  
Embryo Fibroblasts ◽  
Ribosomal S6 Kinase ◽  
Chicken Embryo Fibroblasts ◽  
Ribosomal Protein S6 Kinase

Antiserum raised against recombinant Xenopus ribosomal protein S6 kinase (rsk) was used to identify a 90,000-Mr ribosomal S6 kinase, pp90rsk, in chicken embryo fibroblasts. Adding serum to cells stimulated the phosphorylation of pp90rsk on serine and threonine residues and increased the activity of S6 kinase measured in immune complex assays. Xenopus S6 kinase II and chicken embryo fibroblast pp90rsk had nearly identical phosphopeptide maps.

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