scholarly journals THE CYTONUCLEOPROTEINS OF AMEBAE

1963 ◽  
Vol 19 (3) ◽  
pp. 467-475 ◽  
Author(s):  
Thomas J. Byers ◽  
Dorothy B. Platt ◽  
Lester Goldstein
Keyword(s):  
Amino Acid ◽  
Migration Rate ◽  
Nuclear Proteins ◽  
Interphase Nuclei ◽  
Donor Nucleus ◽  
Equilibrium Ratio ◽  
Protein Label ◽  
Host Nucleus ◽  
In Cells

Radioactivity, apparently in cytonucleoproteins, from an amino acid-labeled nucleus implanted into a non-radioactive cell appeared in the host nucleus within 10 minutes, and the typical equilibrium ratio 70:30 donor nucleus radioactivity:host nucleus radioactivity was reached in 4 to 5 hours at 25°C. If such binucleates grew and divided, no localization of radioactivity was observable in cells fixed during mitosis, but the protein label remained concentrated in the daughter interphase nuclei for at least 4 generations. Continued migration of cytonucleoproteins was observed if these daughter nuclei were transplanted to other unlabeled cells. The Q10 (19° to 29°C) of the migration rate of radioactive cytonucleoproteins was ca. 1.3, suggesting that passage through the cytoplasm occurred by diffusion. Both non-migratory nuclear proteins and cytonucleoproteins appear to be synthesized in the cytoplasm.

Probing nucleus-enriched proteins in single living cells via subcellular-resolved plasmonic immunosandwich assay

The Analyst ◽  
2021 ◽  
Author(s):  
Jia Liu ◽  
Dan Xie ◽  
Zhen Liu
Keyword(s):  
Living Cells ◽  
Nuclear Proteins ◽  
Biological Functions ◽  
Abnormal Expression ◽  
Single Living Cells ◽  
Single Living ◽  
In Cells

Nuclear proteins are crucial in cells and are greatly linked to various biological functions. Abnormal expression of nuclear proteins is associated with many diseases ranging from inflammation to cancer. However,...

The Synthesis and Migration of Nuclear Proteins during Mitosis and differentiation of Cells in Rats

1965 ◽  
Vol s3-106 (75) ◽  
pp. 229-240
Author(s):  
R. T. SIMS
Keyword(s):  
Granular Cell ◽  
Nuclear Proteins ◽  
Photographic Emulsion ◽  
Metaphase Chromosomes ◽  
Interphase Nuclei ◽  
Cell Layers ◽  
The Difference ◽  
Mitotic Figures ◽  
And Migration ◽  
Silver Grains

Hooded rats were given an intraperitoneal injection of 3H-tyrosine, and killed in pairs 10 min, 30 min, 12 h, 36 h, 7 days, and 30 days later. A piece of skin with white growing hair, and the tongue, were taken from each animal and radioautographs were prepared. Silver grains were counted over whole nuclei and whole mitotic figures of the germinal cells and whole nuclei of differentiating cells of both tissues. It was found that the interphase nuclei have significantly more silver grains over them than the chromosomes at all stages of mitosis and there are virtually no grains over metaphase, anaphase, and early telophase chromosomes in both tissues of all the animals killed up to 36 h after the injection. The difference between the grain counts over the interphase nuclei and the chromosomes of dividing cells is at least 20-fold at 30 min in the hair matrix, at least 5-fold at 30 min in the tongue and at 36 h in both tissues. It was established that the differences observed between the radioactivities of the nuclei and chromosomes of mitotic figures are real from estimates of: the radioactivity of the cell cytoplasm, volumes of the metaphase chromosomes and interphase nuclei within 1µ of the photographic emulsion, and the volumes of cytoplasm separating the photographic emulsion and these structures. No protein synthesis was demonstrable in the chromosomes during metaphase, anaphase, and early telophase. Nuclear proteins leave the chromosomes during prophase and prometaphase and return to the nucleus during late telophase. The cells in the matrix and upper bulb of the growing hair follicle and those in the germinal, prickle, and granular cell layers of the tongue are in different functional states; 30 min after injection of 3H-tyrosine they have different amounts of it in their nuclear proteins. It is suggested that the amount incorporated into each nucleus is related to the rate at which proteins are being synthesized by the cell.

Nuclear proteins of quiescent and mitotically active cells in shoot meristems of Tradescantia paludosa

1974 ◽  
Vol 52 (9) ◽  
pp. 2049-2053 ◽  
Author(s):  
R. S. Tobin ◽  
Kyu-Byung Yun ◽  
J. M. Naylor
Keyword(s):  
Nuclear Proteins ◽  
Zone Of Inhibition ◽  
Interphase Nuclei ◽  
Lateral Buds ◽  
Dye Binding ◽  
Tradescantia Paludosa ◽  
Shoot Meristems

In inhibited lateral buds of Tradescantia paludosa, interphase nuclei in the apical zone of inhibition contain higher levels of arginine per unit DNA than those of mitotically active cells in interphase or prophase. Supplementary dye-binding experiments suggest that this reflects a corresponding difference between the composition of the histone complement of chromatin in the two cells populations. The possible implications of this phenomenon are discussed.

Transport of L-tyrosine by B16/F10 melanoma cells: the effect of the intracellular content of other amino acids

1990 ◽  
Vol 97 (3) ◽  
pp. 479-485
Author(s):  
J.R. Jara ◽  
J.H. Martinez-Liarte ◽  
F. Solano ◽  
R. Penafiel
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Initial Rate ◽  
Aromatic Amino Acids ◽  
Melanoma Cells ◽  
Transport Systems ◽  
Specific Amino Acid ◽  
Intracellular Content ◽  
Tyrosine Hydroxylation ◽  
In Cells

The uptake of L-Tyr by B16/F10 malignant melanocytes in culture has been studied. These melanoma cells can either be depleted of amino acids by 1 h preincubation in Hanks' isotonic medium or preloaded with a specific amino acid by 1 h preincubation in the same solution containing 2 mM of the amino acid to be preloaded. By means of these pretreatments, it is shown that the rate of L-Tyr uptake is greatly dependent on the content of other amino acids inside the cells. The L-Tyr uptake is higher in cells preloaded with amino acids transported by the L and ASC systems than in cells depleted of amino acids or preloaded with amino acids transported by the A system. It is concluded that L-Tyr is mainly taken up by an exchange mechanism with other amino acids mediated by the L1 system, although the ASC system can also participate in the process. In agreement with that, the homo-exchange performed by cells preloaded with unlabelled L-Tyr is more efficient than any other hetero-exchange, although L-Dopa, the product of tyrosine hydroxylation in melanin synthesis, is almost as efficient as L-Tyr. Apart from aromatic amino acids, melanoma cells preloaded with L-Met and L-His also yield a high initial rate of L-Tyr uptake. The results herein suggest that melanoma cells do not have transport systems specific for L-Tyr, even if this amino acid is needed to carry out the differential pathway of this type of cells, melanosynthesis.

scholarly journals ATF4-Mediated Upregulation of REDD1 and Sestrin2 Suppresses mTORC1 Activity during Prolonged Leucine Deprivation

2019 ◽  
Vol 150 (5) ◽  
pp. 1022-1030 ◽  
Author(s):  
Dandan Xu ◽  
Weiwei Dai ◽  
Lydia Kutzler ◽  
Holly A Lacko ◽  
Leonard S Jefferson ◽  
...  
Keyword(s):  
Amino Acids ◽  
Dna Damage ◽  
Amino Acid ◽  
Protein Kinase ◽  
Dna Damage Response ◽  
Dependent Manner ◽  
Mouse Embryo Fibroblasts ◽  
Damage Response ◽  
Mtorc1 Activation ◽  
In Cells

ABSTRACT Background The protein kinase target of rapamycin (mTOR) in complex 1 (mTORC1) is activated by amino acids and in turn upregulates anabolic processes. Under nutrient-deficient conditions, e.g., amino acid insufficiency, mTORC1 activity is suppressed and autophagy is activated. Intralysosomal amino acids generated by autophagy reactivate mTORC1. However, sustained mTORC1 activation during periods of nutrient insufficiency would likely be detrimental to cellular homeostasis. Thus, mechanisms must exist to prevent amino acids released by autophagy from reactivating the kinase. Objective The objective of the present study was to test whether mTORC1 activity is inhibited during prolonged leucine deprivation through ATF4-dependent upregulation of the mTORC1 suppressors regulated in development and DNA damage response 1 (REDD1) and Sestrin2. Methods Mice (8 wk old; C57Bl/6 × 129SvEV) were food deprived (FD) overnight and one-half were refed the next morning. Mouse embryo fibroblasts (MEFs) deficient in ATF4, REDD1, and/or Sestrin2 were deprived of leucine for 0–16 h. mTORC1 activity and ATF4, REDD1, and Sestrin2 expression were assessed in liver and cell lysates. Results Refeeding FD mice resulted in activation of mTORC1 in association with suppressed expression of both REDD1 and Sestrin2 in the liver. In cells in culture, mTORC1 exhibited a triphasic response to leucine deprivation, with an initial suppression followed by a transient reactivation from 2 to 4 h and a subsequent resuppression after 8 h. Resuppression occurred concomitantly with upregulated expression of ATF4, REDD1, and Sestrin2. However, in cells lacking ATF4, neither REDD1 nor Sestrin2 expression was upregulated by leucine deprivation, and resuppression of mTORC1 was absent. Moreover, in cells lacking either REDD1 or Sestrin2, mTORC1 resuppression was attenuated, and in cells lacking both proteins resuppression was further blunted. Conclusions The results suggest that leucine deprivation upregulates expression of both REDD1 and Sestrin2 in an ATF4-dependent manner, and that upregulated expression of both proteins is involved in resuppression of mTORC1 during prolonged leucine deprivation.

Evaluation of the Interaction between Bax and Hsp70 in Cells by Using a FRET System Consisting of a Fluorescent Amino Acid and YFP as a FRET Pair

ChemBioChem ◽  
2019 ◽  
Vol 21 (1-2) ◽  
pp. 59-63
Author(s):  
Seong‐Hyun Park ◽  
Wooseok Ko ◽  
Sang‐Hyun Park ◽  
Hyun Soo Lee ◽  
Injae Shin
Keyword(s):  
Amino Acid ◽  
Fluorescent Amino Acid ◽  
Fret Pair ◽  
In Cells

scholarly journals Identification of shorter length lamin A protein in mouse ear cartilage tissue

2015 ◽  
Vol 20 (2) ◽  
Author(s):  
Ramamoorthy M. Kalidas ◽  
Subramanian Elaiya Raja ◽  
Sivasubramaniam Sudhakar
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequence ◽  
Accelerated Aging ◽  
Cartilage Tissue ◽  
Lamin A ◽  
Intermediate Filament Protein ◽  
Mouse Ear ◽  
Ear Cartilage ◽  
Filament Protein ◽  
In Cells

AbstractLamin A is an intermediate filament protein which is cleaved by the enzyme, FACE 1 at VTRSY↓L. The cleavage is the final step in the production of the mature lamin A protein. The mature lamin A protein localizes in the inner membrane of the nucleus. The mutation in the lamin A gene causes many diseases, including accelerated aging. It is known that the protein is not expressed in neuronal cells of the brain. Many splicing variants of the lamin A gene have been reported. In this study, the amino acid sequence VTRSY (a penta-peptide repeat) was found in three different sites of the C-terminal end of the lamin A protein, the protein expressed in cells of ear cartilage tissues is shorter than the protein expressed in cells of the skin tissues. Using two lamin A antibodies, it was found that the amino acid sequence between penta-peptide 2 and 3 is missing in lamin A protein that was expressed in the cells of mouse ear cartilage tissue, besides the RT-PCR data confirmed that the corresponding coding sequence between the penta repeat 2 and 3 is intact. Cleavage may occur at the penta-peptide (VTRSY) at site 3 in the lamin A tail of mouse ear cartilage.

scholarly journals Targeting of Arf-1 to the early Golgi by membrin, an ER-Golgi SNARE

2005 ◽  
Vol 168 (7) ◽  
pp. 1039-1051 ◽  
Author(s):  
Akira Honda ◽  
Omayma S. Al-Awar ◽  
Jesse C. Hay ◽  
Julie G. Donaldson
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequence ◽  
Membrane Traffic ◽  
Snare Protein ◽  
Wild Type ◽  
Rab Family ◽  
In Cells

Arf and Rab family GTPases regulate membrane traffic in cells, yet little is known about how they are targeted to distinct organelles. To identify sequences in Arf-1 necessary for Golgi targeting, we examined the localization of chimeras between Arf-1 and Arf-6. Here, we identify a 16–amino acid sequence in Arf-1 that specifies Golgi targeting and contains a motif (MXXE) that is important for Arf-1 binding to membrin, an ER-Golgi SNARE protein. The MXXE motif is conserved in all Arfs known to localize to the Golgi and enables Arf-1 to localize to the early Golgi. Arf-1 lacking these 16 aa can still localize to the late Golgi where it displays a more rapid Golgi-cytosol cycle than wild-type Arf-1. These studies suggest that membrin recruits Arf-1 to the early Golgi and reveal distinct kinetic cycles for Arf-1 at early and late Golgi determined by different sets of Arf regulators and effectors.

scholarly journals Sequence specificity analysis of the SETD2 protein lysine methyltransferase and discovery of a SETD2 super-substrate

2020 ◽  
Vol 3 (1) ◽  
Author(s):  
Maren Kirstin Schuhmacher ◽  
Serap Beldar ◽  
Mina S. Khella ◽  
Alexander Bröhm ◽  
Jan Ludwig ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Histone H3 ◽  
Protein Methylation ◽  
Sequence Specificity ◽  
Sequence Design ◽  
Substrate Peptide ◽  
Lysine Methyltransferase ◽  
In Cells

AbstractSETD2 catalyzes methylation at lysine 36 of histone H3 and it has many disease connections. We investigated the substrate sequence specificity of SETD2 and identified nine additional peptide and one protein (FBN1) substrates. Our data showed that SETD2 strongly prefers amino acids different from those in the H3K36 sequence at several positions of its specificity profile. Based on this, we designed an optimized super-substrate containing four amino acid exchanges and show by quantitative methylation assays with SETD2 that the super-substrate peptide is methylated about 290-fold more efficiently than the H3K36 peptide. Protein methylation studies confirmed very strong SETD2 methylation of the super-substrate in vitro and in cells. We solved the structure of SETD2 with bound super-substrate peptide containing a target lysine to methionine mutation, which revealed better interactions involving three of the substituted residues. Our data illustrate that substrate sequence design can strongly increase the activity of protein lysine methyltransferases.

scholarly journals mTOR Inhibition Restores Amino Acid Balance in Cells Dependent on Catabolism of Extracellular Protein

2017 ◽  
Vol 67 (6) ◽  
pp. 936-946.e5 ◽  
Author(s):  
Michel Nofal ◽  
Kevin Zhang ◽  
Seunghun Han ◽  
Joshua D. Rabinowitz
Keyword(s):  
Amino Acid ◽  
Extracellular Protein ◽  
Mtor Inhibition ◽  
Amino Acid Balance ◽  
In Cells
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