The Drosophila GenetaranisEncodes a Novel Trithorax Group Member Potentially Linked to the Cell Cycle Regulatory Apparatus

Genetics ◽  
2002 ◽  
Vol 160 (2) ◽  
pp. 547-560 ◽  
Author(s):  
Stéphane Calgaro ◽  
Muriel Boube ◽  
David L Cribbs ◽  
Henri-Marc Bourbon
Keyword(s):  
Cell Cycle ◽  
Chromatin Structure ◽  
Protein A ◽  
Protein Isoforms ◽  
Alternative Promoters ◽  
Loss Of Function ◽  
Trithorax Group ◽  
Evolutionarily Conserved ◽  
Cycle Regulation ◽  
Group Member

AbstractGenes of the Drosophila Polycomb and trithorax groups (PcG and trxG, respectively) influence gene expression by modulating chromatin structure. Segmental expression of homeotic loci (HOM) initiated in early embryogenesis is maintained by a balance of antagonistic PcG (repressor) and trxG (activator) activities. Here we identify a novel trxG family member, taranis (tara), on the basis of the following criteria: (i) tara loss-of-function mutations act as genetic antagonists of the PcG genes Polycomb and polyhomeotic and (ii) they enhance the phenotypic effects of mutations in the trxG genes trithorax (trx), brahma (brm), and osa. In addition, reduced tara activity can mimic homeotic loss-of-function phenotypes, as is often the case for trxG genes. tara encodes two closely related 96-kD protein isoforms (TARA-α/-β) derived from broadly expressed alternative promoters. Genetic and phenotypic rescue experiments indicate that the TARA-α/-β proteins are functionally redundant. The TARA proteins share evolutionarily conserved motifs with several recently characterized mammalian nuclear proteins, including the cyclin-dependent kinase regulator TRIP-Br1/p34SEI-1, the related protein TRIP-Br2/Y127, and RBT1, a partner of replication protein A. These data raise the possibility that TARA-α/-β play a role in integrating chromatin structure with cell cycle regulation.

The domino gene of Drosophila encodes novel members of the SWI2/SNF2 family of DNA-dependent ATPases, which contribute to the silencing of homeotic genes

Development ◽  
2001 ◽  
Vol 128 (8) ◽  
pp. 1429-1441 ◽  
Author(s):  
M.L. Ruhf ◽  
A. Braun ◽  
O. Papoulas ◽  
J.W. Tamkun ◽  
N. Randsholt ◽  
...  
Keyword(s):  
Polytene Chromosomes ◽  
Gene Mutations ◽  
Polycomb Group ◽  
Protein Isoforms ◽  
Homeotic Genes ◽  
Loss Of Function ◽  
Trithorax Group ◽  
A Subunit ◽  
The Common ◽  
Hematopoietic Disorders

The Drosophila domino gene has been isolated in a screen for mutations that cause hematopoietic disorders. Generation and analysis of loss-of-function domino alleles show that the phenotypes are typical for proliferation gene mutations. Clonal analysis demonstrates that domino is necessary for cell viability and proliferation, as well as for oogenesis. domino encodes two protein isoforms of 3202 and 2498 amino acids, which contain a common N-terminal region but divergent C termini. The common region includes a 500 amino acid DNA-dependent ATPase domain of the SWI2/SNF2 family of proteins, which function via interaction with chromatin. We show that, although domino alleles do not exhibit homeotic phenotypes by themselves, domino mutations enhance Polycomb group mutations and counteract Trithorax group effects. The Domino proteins are present in large complexes in embryo extracts, and one isoform binds to a number of discrete sites on larval polytene chromosomes. Altogether, the data lead us to propose that domino acts as a repressor by interfering with chromatin structure. This activity is likely to be performed as a subunit of a chromatin-remodeling complex.

The Drosophila Hrb98DE locus encodes four protein isoforms homologous to the A1 protein of mammalian heterogeneous nuclear ribonucleoprotein complexes

1990 ◽  
Vol 10 (1) ◽  
pp. 316-323
Author(s):  
S R Haynes ◽  
G Raychaudhuri ◽  
A L Beyer
Keyword(s):  
Protein A ◽  
Protein Isoforms ◽  
Alternative Promoters ◽  
Splice Acceptor ◽  
Heterogeneous Nuclear Ribonucleoprotein ◽  
Rich Domain ◽  
Ribonucleoprotein Complexes ◽  
Early Embryos ◽  
Protein Components ◽  
Nuclear Ribonucleoprotein

The Drosophila Hrb98DE locus encodes proteins that are highly homologous to the mammalian A1 protein, a major component of heterogeneous nuclear ribonucleoprotein (RNP) particles. The Hrb98DE locus is transcribed throughout development, with the highest transcript levels found in ovaries, early embryos, and pupae. Eight different transcripts are produced by the use of combinations of alternative promoters, exons, and splice acceptor sites; the various species are not all equally abundant. The 3'-most exon is unusual in that it is completely noncoding. These transcripts can potentially generate four protein isoforms that differ in their N-terminal 16 to 21 amino acids but are identical in the remainder of the protein, including the RNP consensus motif domain and the glycine-rich domain characteristic of the mammalian A1 protein. We suggest that these sequence differences could affect the affinities of the proteins for RNA or other protein components of heterogeneous nuclear RNP complexes, leading to differences in function.

scholarly journals Cell Cycle Regulation of DNA Replication Initiator Factor Dbf4p

1999 ◽  
Vol 19 (6) ◽  
pp. 4270-4278 ◽  
Author(s):  
Liang Cheng ◽  
Tim Collyer ◽  
Christopher F. J. Hardy
Keyword(s):  
Cell Cycle ◽  
Dna Damage ◽  
Dna Replication ◽  
Genetic Material ◽  
Anaphase Promoting Complex ◽  
Initiator Protein ◽  
Evolutionarily Conserved ◽  
M Phase ◽  
Cycle Regulation ◽  
Replication Initiator

ABSTRACT The precise duplication of eukaryotic genetic material takes place once and only once per cell cycle and is dependent on the completion of the previous mitosis. Two evolutionarily conserved kinases, the cyclin B (Clb)/cyclin-dependent kinase (Cdk/Cdc28p) and Cdc7p along with its interacting factor Dbf4p, are required late in G1 to initiate DNA replication. We have determined that the levels of Dbf4p are cell cycle regulated. Dbf4p levels increase as cells begin S phase and remain high through late mitosis, after which they decline dramatically as cells begin the next cell cycle. We report that Dbf4p levels are sensitive to mutations in key components of the anaphase-promoting complex (APC). In addition, Dbf4p is modified in response to DNA damage, and this modification is dependent upon the DNA damage response pathway. We had previously shown that Dbf4p interacts with the M phase polo-like kinase Cdc5p, a key regulator of the APC late in mitosis. These results further link the actions of the initiator protein, Dbf4p, to the completion of mitosis and suggest possible roles for Dbf4p during progression through mitosis.

scholarly journals Phosphorylation by Casein Kinase 2 Regulates Nap1 Localization and Function

2007 ◽  
Vol 28 (4) ◽  
pp. 1313-1325 ◽  
Author(s):  
Meredith E. K. Calvert ◽  
Kristin M. Keck ◽  
Celeste Ptak ◽  
Jeffrey Shabanowitz ◽  
Donald F. Hunt ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Casein Kinase ◽  
Casein Kinase 2 ◽  
S Phase ◽  
Bud Formation ◽  
Evolutionarily Conserved ◽  
Assembly Factor ◽  
And Function ◽  
Cycle Regulation

ABSTRACT In Saccharomyces cerevisiae, the evolutionarily conserved nucleocytoplasmic shuttling protein Nap1 is a cofactor for the import of histones H2A and H2B, a chromatin assembly factor and a mitotic factor involved in regulation of bud formation. To understand the mechanism by which Nap1 function is regulated, Nap1-interacting factors were isolated and identified by mass spectrometry. We identified several kinases among these proteins, including casein kinase 2 (CK2), and a new bud neck-associated protein, Nba1. Consistent with our identification of the Nap1-interacting kinases, we showed that Nap1 is phosphorylated in vivo at 11 sites and that Nap1 is phosphorylated by CK2 at three substrate serines. Phosphorylation of these serines was not necessary for normal bud formation, but mutation of these serines to either alanine or aspartic acid resulted in cell cycle changes, including a prolonged S phase, suggesting that reversible phosphorylation by CK2 is important for cell cycle regulation. Nap1 can shuttle between the nucleus and cytoplasm, and we also showed that CK2 phosphorylation promotes the import of Nap1 into the nucleus. In conclusion, our data show that Nap1 phosphorylation by CK2 appears to regulate Nap1 localization and is required for normal progression through S phase.

scholarly journals Cell Cycle Regulation of the Saccharomyces cerevisiae Polo-Like Kinase Cdc5p

1998 ◽  
Vol 18 (12) ◽  
pp. 7360-7370 ◽  
Author(s):  
Liang Cheng ◽  
Linda Hunke ◽  
Christopher F. J. Hardy
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cell Cycle ◽  
Cell Cycle Regulation ◽  
Kinase Activity ◽  
Anaphase Promoting Complex ◽  
Mitotic Kinases ◽  
Polo Kinase ◽  
Evolutionarily Conserved ◽  
M Phase ◽  
Cycle Regulation

ABSTRACT Progression through and completion of mitosis require the actions of the evolutionarily conserved Polo kinase. We have determined that the levels of Cdc5p, a Saccharomyces cerevisiae member of the Polo family of mitotic kinases, are cell cycle regulated. Cdc5p accumulates in the nuclei of G2/M-phase cells, and its levels decline dramatically as cells progress through anaphase and begin telophase. We report that Cdc5p levels are sensitive to mutations in key components of the anaphase-promoting complex (APC). We have determined that Cdc5p-associated kinase activity is restricted to G2/M and that this activity is posttranslationally regulated. These results further link the actions of the APC to the completion of mitosis and suggest possible roles for Cdc5p during progression through and completion of mitosis.

scholarly journals The Drosophila Hrb98DE locus encodes four protein isoforms homologous to the A1 protein of mammalian heterogeneous nuclear ribonucleoprotein complexes.

1990 ◽  
Vol 10 (1) ◽  
pp. 316-323 ◽  
Author(s):  
S R Haynes ◽  
G Raychaudhuri ◽  
A L Beyer
Keyword(s):  
Protein A ◽  
Protein Isoforms ◽  
Alternative Promoters ◽  
Splice Acceptor ◽  
Heterogeneous Nuclear Ribonucleoprotein ◽  
Rich Domain ◽  
Ribonucleoprotein Complexes ◽  
Early Embryos ◽  
Protein Components ◽  
Nuclear Ribonucleoprotein

The Drosophila Hrb98DE locus encodes proteins that are highly homologous to the mammalian A1 protein, a major component of heterogeneous nuclear ribonucleoprotein (RNP) particles. The Hrb98DE locus is transcribed throughout development, with the highest transcript levels found in ovaries, early embryos, and pupae. Eight different transcripts are produced by the use of combinations of alternative promoters, exons, and splice acceptor sites; the various species are not all equally abundant. The 3'-most exon is unusual in that it is completely noncoding. These transcripts can potentially generate four protein isoforms that differ in their N-terminal 16 to 21 amino acids but are identical in the remainder of the protein, including the RNP consensus motif domain and the glycine-rich domain characteristic of the mammalian A1 protein. We suggest that these sequence differences could affect the affinities of the proteins for RNA or other protein components of heterogeneous nuclear RNP complexes, leading to differences in function.

A Misexpression Study Examining Dorsal Thorax Formation in Drosophila melanogaster

Genetics ◽  
2002 ◽  
Vol 160 (3) ◽  
pp. 1035-1050
Author(s):  
María Teresa Peña-Rangel ◽  
Isabel Rodriguez ◽  
Juan Rafael Riesgo-Escovar
Keyword(s):  
Cell Cycle ◽  
Drosophila Melanogaster ◽  
Chromatin Remodeling ◽  
Cell Cycle Regulation ◽  
Transcriptional Control ◽  
Genetic Data ◽  
Loss Of Function ◽  
Functional Roles ◽  
Chromatin Remodeling Complex ◽  
Cycle Regulation

Abstract We studied thorax formation in Drosophila melanogaster using a misexpression screen with EP lines and thoracic Gal4 drivers that provide a genetically sensitized background. We identified 191 interacting lines showing alterations of thoracic bristles (number and/or location), thorax and scutellum malformations, lethality, or suppression of the thoracic phenotype used in the screen. We analyzed these lines and showed that known genes with different functional roles (selector, prepattern, proneural, cell cycle regulation, lineage restriction, signaling pathways, transcriptional control, and chromatin organization) are among the modifier lines. A few lines have previously been identified in thorax formation, but others, such as chromatin-remodeling complex genes, are novel. However, most of the interacting loci are uncharacterized, providing a wealth of new genetic data. We also describe one such novel line, poco pelo (ppo), where both misexpression and loss-of-function phenotypes are similar: loss of bristles and scutellum malformation.

scholarly journals The ATR-WEE1 kinase module inhibits the MAC complex to regulate replication stress response

2021 ◽  
Vol 49 (3) ◽  
pp. 1411-1425 ◽  
Author(s):  
Lili Wang ◽  
Li Zhan ◽  
Yan Zhao ◽  
Yongchi Huang ◽  
Chong Wu ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Stress Responses ◽  
Genome Stability ◽  
Intron Retention ◽  
Cell Cycle Control ◽  
Replication Stress ◽  
Loss Of Function ◽  
Evolutionarily Conserved ◽  
Subsequent Degradation ◽  
Wee1 Kinase

Abstract DNA damage response is a fundamental mechanism to maintain genome stability. The ATR-WEE1 kinase module plays a central role in response to replication stress. Although the ATR-WEE1 pathway has been well studied in yeasts and animals, how ATR-WEE1 functions in plants remains unclear. Through a genetic screen for suppressors of the Arabidopsis atr mutant, we found that loss of function of PRL1, a core subunit of the evolutionarily conserved MAC complex involved in alternative splicing, suppresses the hypersensitivity of atr and wee1 to replication stress. Biochemical studies revealed that WEE1 directly interacts with and phosphorylates PRL1 at Serine 145, which promotes PRL1 ubiquitination and subsequent degradation. In line with the genetic and biochemical data, replication stress induces intron retention of cell cycle genes including CYCD1;1 and CYCD3;1, which is abolished in wee1 but restored in wee1 prl1. Remarkably, co-expressing the coding sequences of CYCD1;1 and CYCD3;1 partially restores the root length and HU response in wee1 prl1. These data suggested that the ATR-WEE1 module inhibits the MAC complex to regulate replication stress responses. Our study discovered PRL1 or the MAC complex as a key downstream regulator of the ATR-WEE1 module and revealed a novel cell cycle control mechanism.

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