scholarly journals The Transcriptional Coactivator SAYP Is a Trithorax Group Signature Subunit of the PBAP Chromatin Remodeling Complex

2008 ◽  
Vol 28 (9) ◽  
pp. 2920-2929 ◽  
Author(s):  
Gillian E. Chalkley ◽  
Yuri M. Moshkin ◽  
Karin Langenberg ◽  
Karel Bezstarosti ◽  
Andras Blastyak ◽  
...  
Keyword(s):  
Chromatin Remodeling ◽  
Polytene Chromosomes ◽  
Group Signature ◽  
Transcriptional Coactivator ◽  
Trithorax Group ◽  
Phd Finger ◽  
Gene Expression Control ◽  
Larval Salivary Gland ◽  
Eukaryotic Gene ◽  
Chromatin Remodeling Complexes

ABSTRACT SWI/SNF ATP-dependent chromatin remodeling complexes (remodelers) perform critical functions in eukaryotic gene expression control. BAP and PBAP are the fly representatives of the two evolutionarily conserved major subclasses of SWI/SNF remodelers. Both complexes share seven core subunits, including the Brahma ATPase, but differ in a few signature subunits; POLYBROMO and BAP170 specify PBAP, whereas OSA defines BAP. Here, we show that the transcriptional coactivator and PHD finger protein SAYP is a novel PBAP subunit. Biochemical analysis established that SAYP is tightly associated with PBAP but absent from BAP. SAYP, POLYBROMO, and BAP170 display an intimately overlapping distribution on larval salivary gland polytene chromosomes. Genome-wide expression analysis revealed that SAYP is critical for PBAP-dependent transcription. SAYP is required for normal development and interacts genetically with core- and PBAP-selective subunits. Genetic analysis suggested that, like BAP, PBAP also counteracts Polycomb silencing. SAYP appears to be a key architectural component required for the integrity and association of the PBAP-specific module. We conclude that SAYP is a signature subunit that plays a major role in the functional specificity of the PBAP holoenzyme.

scholarly journals Differential Targeting of Two Distinct SWI/SNF-Related Drosophila Chromatin-Remodeling Complexes

2004 ◽  
Vol 24 (8) ◽  
pp. 3077-3088 ◽  
Author(s):  
Lisette Mohrmann ◽  
Karin Langenberg ◽  
Jeroen Krijgsveld ◽  
Arnoud J. Kal ◽  
Albert J. R. Heck ◽  
...  
Keyword(s):  
Chromatin Remodeling ◽  
Polytene Chromosomes ◽  
Distribution Patterns ◽  
Human Cells ◽  
Genome Wide ◽  
Larval Salivary Gland ◽  
Associated Proteins ◽  
Chromatin Remodeling Complexes ◽  
Distinct Distribution

ABSTRACT The SWI/SNF family of ATP-dependent chromatin-remodeling factors plays a central role in eukaryotic transcriptional regulation. In yeast and human cells, two subclasses have been recognized: one comprises yeast SWI/SNF and human BAF, and the other includes yeast RSC and human PBAF. Therefore, it was puzzling that Drosophila appeared to contain only a single SWI/SNF-type remodeler, the Brahma (BRM) complex. Here, we report the identification of two novel BRM complex-associated proteins: Drosophila Polybromo and BAP170, a conserved protein not described previously. Biochemical analysis established that Drosophila contains two distinct BRM complexes: (i) the BAP complex, defined by the presence of OSA and the absence of Polybromo and BAP170, and (ii) the PBAP complex, containing Polybromo and BAP170 but lacking OSA. Determination of the genome-wide distributions of OSA and Polybromo on larval salivary gland polytene chromosomes revealed that BAP and PBAP display overlapping but distinct distribution patterns. Both complexes associate predominantly with regions of open, hyperacetylated chromatin but are largely excluded from Polycomb-bound repressive chromatin. We conclude that, like yeast and human cells, Drosophila cells express two distinct subclasses of the SWI/SNF family. Our results support a close reciprocity of chromatin regulation by ATP-dependent remodelers and histone-modifying enzymes.

The Drosophila trithorax group proteins BRM, ASH1 and ASH2 are subunits of distinct protein complexes

Development ◽  
1998 ◽  
Vol 125 (20) ◽  
pp. 3955-3966 ◽  
Author(s):  
O. Papoulas ◽  
S.J. Beek ◽  
S.L. Moseley ◽  
C.M. McCallum ◽  
M. Sarte ◽  
...  
Keyword(s):  
Chromatin Remodeling ◽  
Protein Complexes ◽  
Dominant Negative ◽  
Homeotic Genes ◽  
Atpase Subunit ◽  
Trithorax Group ◽  
Chromatin Remodeling Complexes ◽  
Trithorax Group Proteins ◽  
Drosophila Embryos

The trithorax group gene brahma (brm) encodes an activator of Drosophila homeotic genes that functions as the ATPase subunit of a large protein complex. To determine if BRM physically interacts with other trithorax group proteins, we purified the BRM complex from Drosophila embryos and analyzed its subunit composition. The BRM complex contains at least seven major polypeptides. Surprisingly, the majority of the subunits of the BRM complex are not encoded by trithorax group genes. Furthermore, a screen for enhancers of a dominant-negative brm mutation identified only one trithorax group gene, moira (mor), that appears to be essential for brm function in vivo. Four of the subunits of the BRM complex are related to subunits of the yeast chromatin remodeling complexes SWI/SNF and RSC. The BRM complex is even more highly related to the human BRG1 and hBRM complexes, but lacks the subunit heterogeneity characteristic of these complexes. We present biochemical evidence for the existence of two additional complexes containing trithorax group proteins: a 2 MDa ASH1 complex and a 500 kDa ASH2 complex. These findings suggest that BRM plays a role in chromatin remodeling that is distinct from the function of most other trithorax group proteins.

scholarly journals The Drosophila ash1 Gene Product, Which Is Localized at Specific Sites on Polytene Chromosomes, Contains a SET Domain and a PHD Finger

Genetics ◽  
1996 ◽  
Vol 143 (2) ◽  
pp. 913-928 ◽  
Author(s):  
Nicholas Tripoulas ◽  
Dennis LaJeunesse ◽  
John Gildea ◽  
Allen Shearn
Keyword(s):  
Amino Acids ◽  
Polytene Chromosomes ◽  
Protein Product ◽  
Polycomb Group ◽  
Transcriptional Level ◽  
Set Domain ◽  
Trithorax Group ◽  
Phd Finger ◽  
Polycomb Group Genes ◽  
The Stability

Abstract The determined state of Drosophila imaginal discs depends on stable patterns of homeotic gene expression. The stability of these patterns requires the function of the ash1 gene, a member of the trithorax group. The primary translation product of the 7.5-kb ash1 transcript is predicted to be a basic protein of 2144 amino acids. The ASHl protein contains a SET domain and a PHD finger. Both of these motifs are found in the products of some trithorax group and Polycomb group genes. We have determined the nucleotide sequence alterations in 10 ash1 mutant alleles and have examined their mutant phenotype. The best candidate for a null allele is ashl  22. The truncated protein product of this mutant allele is predicted to contain only 47 amino acids. The ASHl protein is localized on polytene chromosomes of larval salivary glands at >100 sites. The chromosomal localization of ASHl implies that it functions at the transcriptional level to maintain the expression pattern of homeotic selector genes.

scholarly journals Roles of the INO80 and SWR1 Chromatin Remodeling Complexes in Plants

2019 ◽  
Vol 20 (18) ◽  
pp. 4591 ◽  
Author(s):  
Jianhao Wang ◽  
Sujuan Gao ◽  
Xiuling Peng ◽  
Keqiang Wu ◽  
Songguang Yang
Keyword(s):  
Gene Expression ◽  
Arabidopsis Thaliana ◽  
Gene Regulation ◽  
Dna Replication ◽  
Chromatin Remodeling ◽  
Eukaryotic Genes ◽  
Eukaryotic Gene ◽  
Chromatin Remodeling Complexes ◽  
Eukaryotic Gene Regulation ◽  
Environmental Responses

Eukaryotic genes are packed into a dynamic but stable nucleoprotein structure called chromatin. Chromatin-remodeling and modifying complexes generate a dynamic chromatin environment that ensures appropriate DNA processing and metabolism in various processes such as gene expression, as well as DNA replication, repair, and recombination. The INO80 and SWR1 chromatin remodeling complexes (INO80-c and SWR1-c) are ATP-dependent complexes that modulate the incorporation of the histone variant H2A.Z into nucleosomes, which is a critical step in eukaryotic gene regulation. Although SWR1-c has been identified in plants, plant INO80-c has not been successfully isolated and characterized. In this review, we will focus on the functions of the SWR1-c and putative INO80-c (SWR1/INO80-c) multi-subunits and multifunctional complexes in Arabidopsis thaliana. We will describe the subunit compositions of the SWR1/INO80-c and the recent findings from the standpoint of each subunit and discuss their involvement in regulating development and environmental responses in Arabidopsis.

Genetic Analysis of the Drosophila 63F Early Puff: Characterization of Mutations in E63-1 and maggie, a Putative Tom22

Genetics ◽  
2000 ◽  
Vol 156 (1) ◽  
pp. 229-244
Author(s):  
Martina Vaskova ◽  
A M Bentley ◽  
Samantha Marshall ◽  
Pamela Reid ◽  
Carl S Thummel ◽  
...  
Keyword(s):  
Salivary Gland ◽  
Genetic Analysis ◽  
Polytene Chromosomes ◽  
Reading Frame ◽  
Protein Levels ◽  
Ef Hand ◽  
Larval Salivary Gland ◽  
Complementation Groups ◽  
Inducible Genes ◽  
Early Puff

Abstract The 63F early puff in the larval salivary gland polytene chromosomes contains the divergently transcribed E63-1 and E63-2 ecdysone-inducible genes. E63-1 encodes a member of the EF-hand family of Ca2+-binding proteins, while E63-2 has no apparent open reading frame. To understand the functions of the E63 genes, we have determined the temporal and spatial patterns of E63-1 protein expression, as well as undertaken a genetic analysis of the 63F puff. We show that E63-1 is expressed in many embryonic and larval tissues, but the third-instar larval salivary gland is the only tissue where increases in protein levels correlate with increases in ecdysone titer. Furthermore, the subcellular distribution of E63-1 protein changes dynamically in the salivary glands at the onset of metamorphosis. E63-1 and E63-2 null mutations, however, have no effect on development or fertility. We have characterized 40 kb of the 63F region, defined as the interval between Ubi-p and E63-2, and have identified three lethal complementation groups that correspond to the dSc-2, ida, and mge genes. We show that mge mutations lead to first-instar larval lethality and that Mge protein is similar to the Tom22 mitochondrial import proteins of fungi, suggesting that it has a role in mitochondrial function.

scholarly journals The trithorax Group Genemoira Encodes a Brahma-Associated Putative Chromatin-Remodeling Factor in Drosophila melanogaster

1999 ◽  
Vol 19 (2) ◽  
pp. 1159-1170 ◽  
Author(s):  
Madeline A. Crosby ◽  
Chaya Miller ◽  
, Tamar Alon ◽  
Kellie L. Watson ◽  
C. Peter Verrijzer ◽  
...  
Keyword(s):  
Drosophila Melanogaster ◽  
Chromatin Remodeling ◽  
Leucine Zipper ◽  
Genetic Relationships ◽  
Fruit Fly ◽  
Protein Product ◽  
Homeotic Genes ◽  
Trithorax Group ◽  
Functional Relationships

ABSTRACT The genes of the trithorax group (trxG) inDrosophila melanogaster are required to maintain the pattern of homeotic gene expression that is established early in embryogenesis by the transient expression of the segmentation genes. The precise role of each of the diverse trxG members and the functional relationships among them are not well understood. Here, we report on the isolation of the trxG gene moira(mor) and its molecular characterization. morencodes a fruit fly homolog of the human and yeast chromatin-remodeling factors BAF170, BAF155, and SWI3. mor is widely expressed throughout development, and its 170-kDa protein product is present in many embryonic tissues. In vitro, MOR can bind to itself and it interacts with Brahma (BRM), an SWI2-SNF2 homolog, with which it is associated in embryonic nuclear extracts. The leucine zipper motif of MOR is likely to participate in self-oligomerization; the equally conserved SANT domain, for which no function is known, may be required for optimal binding to BRM. MOR thus joins BRM and Snf5-related 1 (SNR1), two known Drosophila SWI-SNF subunits that act as positive regulators of the homeotic genes. These observations provide a molecular explanation for the phenotypic and genetic relationships among several of the trxG genes by suggesting that they encode evolutionarily conserved components of a chromatin-remodeling complex.

The trithorax group gene osa encodes an ARID-domain protein that genetically interacts with the brahma chromatin-remodeling factor to regulate transcription

Development ◽  
1999 ◽  
Vol 126 (4) ◽  
pp. 733-742 ◽  
Author(s):  
M. Vazquez ◽  
L. Moore ◽  
J.A. Kennison
Keyword(s):  
Gene Regulation ◽  
Chromatin Remodeling ◽  
Homeotic Gene ◽  
Dna Binding Domain ◽  
Atpase Subunit ◽  
Trithorax Group ◽  
Chromatin Remodeling Complex ◽  
P2 Promoter ◽  
Domain Protein ◽  
Arid Domain

The trithorax group gene brahma (brm) encodes the ATPase subunit of a chromatin-remodeling complex involved in homeotic gene regulation. We report here that brm interacts with another trithorax group gene, osa, to regulate the expression of the Antennapedia P2 promoter. Regulation of Antennapedia by BRM and OSA proteins requires sequences 5′ to the P2 promoter. Loss of maternal osa function causes severe segmentation defects, indicating that the function of osa is not limited to homeotic gene regulation. The OSA protein contains an ARID domain, a DNA-binding domain also present in the yeast SWI1 and Drosophila DRI proteins. We propose that the OSA protein may target the BRM complex to Antennapedia and other regulated genes.

Sign in / Sign up

Export Citation Format

Share Document