scholarly journals Localization and expression of mRNA for a macronuclear-specific histone H2A variant (hv1) during the cell cycle and conjugation of Tetrahymena thermophila.

1988 ◽  
Vol 8 (11) ◽  
pp. 4780-4786 ◽  
Author(s):  
E M White ◽  
M A Gorovsky
Keyword(s):  
Cell Cycle ◽  
In Situ Hybridization ◽  
S Phase ◽  
Histone H2a ◽  
Mrna Accumulation ◽  
Macronuclear Development ◽  
A Cell ◽  
Size And Morphology ◽  
Active Genes

hv1 is a histone H2A variant found in the transcriptionally active Tetrahymena macronucleus but not in the transcriptionally inert micronucleus. This, along with a number of other lines of evidence, suggests that hv1 is associated with active genes. We have used a cDNA clone as a probe to study hv1 mRNA accumulation throughout the cell cycle and during conjugation. In situ hybridization to glutaraldehyde-fixed growing cells, whose position in the cell cycle was determined by size and morphology, showed that hv1 message is present throughout the cell cycle. The message was uniformly distributed in these vegetative cells. Compared with four other Tetrahymena histone genes studied to date (S. -M. Yu, S. Horowitz, and M. A. Gorovsky, Genes Dev., 1:683, 1987; M. Wu, C. D. Allis, and M. A. Gorovsky, Proc. Natl. Acad. Sci. USA 85:2205, 1988), hv1 mRNA is the only one that does not show a pattern of accumulation during the cell cycle that could explain the nuclear localization of its encoded protein. Thus, either hv1 or some molecule with which it associates contains a macronuclear-specific targeting sequence or there exists a cell cycle-regulated event that restricts its translation to the macronuclear S phase. In situ hybridization to conjugating cells revealed that hv1 message amounts increase just prior to macronuclear development and decline precipitously after the cells separate. The hv1 message showed no marked subcellular localization and is, therefore, unlikely to play a role in the cytoplasmic determination known to occur during macronuclear development.

Localization and expression of mRNA for a macronuclear-specific histone H2A variant (hv1) during the cell cycle and conjugation of Tetrahymena thermophila

1988 ◽  
Vol 8 (11) ◽  
pp. 4780-4786
Author(s):  
E M White ◽  
M A Gorovsky
Keyword(s):  
Cell Cycle ◽  
In Situ Hybridization ◽  
S Phase ◽  
Histone H2a ◽  
Mrna Accumulation ◽  
Macronuclear Development ◽  
A Cell ◽  
Size And Morphology ◽  
Active Genes

hv1 is a histone H2A variant found in the transcriptionally active Tetrahymena macronucleus but not in the transcriptionally inert micronucleus. This, along with a number of other lines of evidence, suggests that hv1 is associated with active genes. We have used a cDNA clone as a probe to study hv1 mRNA accumulation throughout the cell cycle and during conjugation. In situ hybridization to glutaraldehyde-fixed growing cells, whose position in the cell cycle was determined by size and morphology, showed that hv1 message is present throughout the cell cycle. The message was uniformly distributed in these vegetative cells. Compared with four other Tetrahymena histone genes studied to date (S. -M. Yu, S. Horowitz, and M. A. Gorovsky, Genes Dev., 1:683, 1987; M. Wu, C. D. Allis, and M. A. Gorovsky, Proc. Natl. Acad. Sci. USA 85:2205, 1988), hv1 mRNA is the only one that does not show a pattern of accumulation during the cell cycle that could explain the nuclear localization of its encoded protein. Thus, either hv1 or some molecule with which it associates contains a macronuclear-specific targeting sequence or there exists a cell cycle-regulated event that restricts its translation to the macronuclear S phase. In situ hybridization to conjugating cells revealed that hv1 message amounts increase just prior to macronuclear development and decline precipitously after the cells separate. The hv1 message showed no marked subcellular localization and is, therefore, unlikely to play a role in the cytoplasmic determination known to occur during macronuclear development.

scholarly journals Cell cycle–dependent localization of macroH2A in chromatin of the inactive X chromosome

2002 ◽  
Vol 157 (7) ◽  
pp. 1113-1123 ◽  
Author(s):  
Brian P. Chadwick ◽  
Huntington F. Willard
Keyword(s):  
Cell Cycle ◽  
X Chromosome ◽  
Degradation Pathway ◽  
S Phase ◽  
Histone H2a ◽  
The Core ◽  
Inactive X Chromosome ◽  
Inactivation Center ◽  
Chromatin Proteins ◽  
Cycle Dependent

One of several features acquired by chromatin of the inactive X chromosome (Xi) is enrichment for the core histone H2A variant macroH2A within a distinct nuclear structure referred to as a macrochromatin body (MCB). In addition to localizing to the MCB, macroH2A accumulates at a perinuclear structure centered at the centrosome. To better understand the association of macroH2A1 with the centrosome and the formation of an MCB, we investigated the distribution of macroH2A1 throughout the somatic cell cycle. Unlike Xi-specific RNA, which associates with the Xi throughout interphase, the appearance of an MCB is predominantly a feature of S phase. Although the MCB dissipates during late S phase and G2 before reforming in late G1, macroH2A1 remains associated during mitosis with specific regions of the Xi, including at the X inactivation center. This association yields a distinct macroH2A banding pattern that overlaps with the site of histone H3 lysine-4 methylation centered at the DXZ4 locus in Xq24. The centrosomal pool of macroH2A1 accumulates in the presence of an inhibitor of the 20S proteasome. Therefore, targeting of macroH2A1 to the centrosome is likely part of a degradation pathway, a mechanism common to a variety of other chromatin proteins.

scholarly journals JunB Breakdown in Mid-/Late G2 Is Required for Down-Regulation of Cyclin A2 Levels and Proper Mitosis

2008 ◽  
Vol 28 (12) ◽  
pp. 4173-4187 ◽  
Author(s):  
Rosa Farràs ◽  
Véronique Baldin ◽  
Sandra Gallach ◽  
Claire Acquaviva ◽  
Guillaume Bossis ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Tumor Suppressor ◽  
Genetic Instability ◽  
S Phase ◽  
Subsequent Reduction ◽  
Suppressor Activity ◽  
Cell Synchronization ◽  
Tumor Suppressor Activity ◽  
A Cell ◽  
Cyclin A2

ABSTRACT JunB, a member of the AP-1 family of dimeric transcription factors, is best known as a cell proliferation inhibitor, a senescence inducer, and a tumor suppressor, although it also has been attributed a cell division-promoting activity. Its effects on the cell cycle have been studied mostly in G1 and S phases, whereas its role in G2 and M phases still is elusive. Using cell synchronization experiments, we show that JunB levels, which are high in S phase, drop during mid- to late G2 phase due to accelerated phosphorylation-dependent degradation by the proteasome. The forced expression of an ectopic JunB protein in late G2 phase indicates that JunB decay is necessary for the subsequent reduction of cyclin A2 levels in prometaphase, the latter event being essential for proper mitosis. Consistently, abnormal JunB expression in late G2 phase entails a variety of mitotic defects. As these aberrations may cause genetic instability, our findings contrast with the acknowledged tumor suppressor activity of JunB and reveal a mechanism by which the deregulation of JunB might contribute to tumorigenesis.

Control of proliferin gene expression in serum-stimulated mouse cells

1987 ◽  
Vol 7 (6) ◽  
pp. 2080-2086
Author(s):  
D I Linzer ◽  
E L Wilder
Keyword(s):  
Protein Synthesis ◽  
S Phase ◽  
Mrna Levels ◽  
3T3 Cells ◽  
Serum Stimulation ◽  
Posttranscriptional Processing ◽  
A Cell ◽  
Mouse Cells ◽  
Stimulation Of

The serum-inducible expression of proliferin genes in BALB/c 3T3 cells was found to be dependent on both protein synthesis and an extended presence of serum in the medium. Even though no mature proliferin mRNA was detected in serum-starved cells, transcription of the proliferin genes occurred in these resting-cell cultures, indicating that posttranscriptional events may be important for regulating proliferin mRNA levels. These results suggest that protein synthesis after serum stimulation of quiescent mouse fibroblasts is required for posttranscriptional processing or stabilization of proliferin RNA. Proliferin RNA levels were found to be heterogeneous among serum-stimulated cells analyzed by in situ hybridization. This heterogeneity is probably due to asynchrony in the population and may point to a correlation between the time of proliferin expression and the time of entry of a cell into S phase.

In situ hybridization reveals differential spatial distribution of mRNAs for type I and type II collagen in the chick limb bud

Development ◽  
1988 ◽  
Vol 103 (1) ◽  
pp. 111-118 ◽  
Author(s):  
C.J. Devlin ◽  
P.M. Brickell ◽  
E.R. Taylor ◽  
A. Hornbruch ◽  
R.K. Craig ◽  
...  
Keyword(s):  
In Situ Hybridization ◽  
Limb Development ◽  
Type I Collagen ◽  
Type Ii Collagen ◽  
Limb Bud ◽  
Type I ◽  
Type Ii ◽  
Mrna Accumulation ◽  
Rna Probes

During limb development, type I collagen disappears from the region where cartilage develops and synthesis of type II collagen, which is characteristic of cartilage, begins. In situ hybridization using antisense RNA probes was used to investigate the spatial localization of type I and type II collagen mRNAs. The distribution of the mRNA for type II collagen corresponded well with the pattern of type II collagen synthesis, suggesting control at the level of transcription and mRNA accumulation. In contrast, the pattern of mRNA for type I collagen remained more or less uniform and did not correspond with the synthesis of the protein, suggesting control primarily at the level of translation or of RNA processing.

scholarly journals The INO80 complex activates the transcription of S‐phase genes in a cell cycle‐regulated manner

FEBS Journal ◽  
2018 ◽  
Vol 285 (20) ◽  
pp. 3870-3881 ◽  
Author(s):  
Iva Knezevic ◽  
Alberto González‐Medina ◽  
Laura Gaspa ◽  
Elena Hidalgo ◽  
José Ayté
Keyword(s):  
Cell Cycle ◽  
S Phase ◽  
A Cell

scholarly journals Control of proliferin gene expression in serum-stimulated mouse cells.

1987 ◽  
Vol 7 (6) ◽  
pp. 2080-2086 ◽  
Author(s):  
D I Linzer ◽  
E L Wilder
Keyword(s):  
Protein Synthesis ◽  
S Phase ◽  
Mrna Levels ◽  
3T3 Cells ◽  
Serum Stimulation ◽  
Posttranscriptional Processing ◽  
A Cell ◽  
Mouse Cells ◽  
Stimulation Of

The serum-inducible expression of proliferin genes in BALB/c 3T3 cells was found to be dependent on both protein synthesis and an extended presence of serum in the medium. Even though no mature proliferin mRNA was detected in serum-starved cells, transcription of the proliferin genes occurred in these resting-cell cultures, indicating that posttranscriptional events may be important for regulating proliferin mRNA levels. These results suggest that protein synthesis after serum stimulation of quiescent mouse fibroblasts is required for posttranscriptional processing or stabilization of proliferin RNA. Proliferin RNA levels were found to be heterogeneous among serum-stimulated cells analyzed by in situ hybridization. This heterogeneity is probably due to asynchrony in the population and may point to a correlation between the time of proliferin expression and the time of entry of a cell into S phase.

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