The sequential phosphorylation of PHF10 subunit of the PBAF chromatin-remodeling complex determines different properties of the PHF10 isoforms.

The mammalian PBAF subfamily of SWI/SNF chromatin remodeling complexes plays a wide role in the regulation of gene expression. PHF10 is a subunit of the signature module of PBAF, responsible for its interaction with chromatin. PHF10 is represented by four different isoforms, which are alternatively incorporated in the complex.

TRF4, the novel TBP-related protein of Drosophila melanogaster, is concentrated at the endoplasmic reticulum and copurifies with proteins participating in the processes associated with endoplasmic reticulum.

Understanding the functions of TBP-related factors is essential for studying chromatin assembly and transcription regulation in higher eukaryotes. The novel TBP-related protein-coding gene, trf4, was described in Drosophila melanogaster. trf4 is found only in Drosophila and has likely originated in Drosophila common ancestor.

ORC interacts with THSC/TREX-2 and its subunits promote Nxf1 association with mRNP and mRNA export in Drosophila.

The origin recognition complex (ORC) of eukaryotes associates with the replication origins and initiates the pre-replication complex assembly. In the literature, there are several reports of interaction of ORC with different RNAs. Here, we demonstrate for the first time a direct interaction of ORC with the THSC/TREX-2 mRNA nuclear export complex.

Insulator protein Su(Hw) recruits SAGA and Brahma complexes and constitutes part of Origin Recognition Complex-binding sites in the Drosophila genome.

Despite increasing data on the properties of replication origins, molecular mechanisms underlying origin recognition complex (ORC) positioning in the genome are still poorly understood. The Su(Hw) protein accounts for the activity of best-studied Drosophila insulators. Here, we show that Su(Hw) recruits the histone acetyltransferase complex SAGA and chromatin remodeler Brahma to Su(Hw)-dependent insulators, which gives rise to regions with low nucleosome density and creates conditions for ORC binding.

The DUBm subunit Sgf11 is required for mRNA export and interacts with Cbp80 in Drosophila.

SAGA/TFTC is a histone acetyltransferase complex that has a second enzymatic activity because of the presence of a deubiquitination module (DUBm). Drosophila DUBm consists of Sgf11, ENY2 and Nonstop proteins. We show that Sgf11 has other DUBm-independent functions.

SAYP and Brahma are important for 'repressive' and 'transient' Pol II pausing.

Drosophila SAYP, a homologue of human PHF10/BAF45a, is a metazoan coactivator associated with Brahma and essential for its recruitment on the promoter. The role of SAYP in DHR3 activator-driven transcription of the ftz-f1 gene, a member of the ecdysone cascade was studied. In the repressed state of ftz-f1 in the presence of DHR3, the Pol II complex is pre-recruited on the promoter; Pol II starts transcription but is paused 1.

Transcription co-activator SAYP mediates the action of STAT activator.

Jak/STAT is an important signaling pathway mediating multiple events in development. We describe participation of metazoan co-activator SAYP/PHF10 in this pathway downstream of STAT. The latter, via its activation domain, interacts with the conserved core of SAYP.

SAYP interacts with DHR3 nuclear receptor and participates in ecdysone-dependent transcription regulation.

The role of metazoan coactivator SAYP in nuclear receptor-driven gene activation in the ecdysone cascade of Drosophila is considered. SAYP interacts with DHR3 nuclear receptor and activates the corresponding genes by recruiting the BTFly (Brahma and TFIID) coactivator supercomplex. The knockdown of SAYP leads to a decrease in the level of DHR3-activated transcription.

ENY2: couple, triple...more?

ENY2/Sus1, a protein involved in the coupling of transcription with mRNA export, is a component of SAGA/TFTC and TREX-2/AMEX complexes. Recently, we have described the association of ENY2 with the third protein complex, THO. Moreover, our data indicate that ENY2 is also associated with other factors, both in the nucleus and cytoplasm.

Multifunctional factor ENY2 is associated with the THO complex and promotes its recruitment onto nascent mRNA.

Metazoan E(y)2/ENY2 is a multifunctional protein important for transcription activation and mRNA export, being a component of SAGA/TFTC and the mRNA export complex AMEX. Here, we show that ENY2 in Drosophila is also stably associated with THO, the complex involved in mRNP biogenesis. The ENY2-THO complex is required for normal Drosophila development, functioning independently on SAGA and AMEX.

The novel regulator of metazoan development SAYP organizes a nuclear coactivator supercomplex.

SAYP is a dual-function transcription coactivator of RNA polymerase II. It is a metazoan-specific factor with regulated expression that is apparently involved in signaling pathways controlling normal development. In Drosophila, SAYP is maternally loaded into the embryo, participates in cell cycle synchronization in early syncytial embryos, and is indispensible for early embryogenesis.

Transcription coactivator SAYP combines chromatin remodeler Brahma and transcription initiation factor TFIID into a single supercomplex.

Transcription activation by RNA polymerase II is a complicated process driven by combined, precisely coordinated action of a wide array of coactivator complexes, which carry out chromatin-directed activities and nucleate the assembly of the preinitiation complex on the promoter. Using various techniques, we have shown the existence of a stable coactivator supercomplex consisting of the chromatin-remodeling factor Brahma (SWI/SNF) and the transcription initiation factor TFIID, named BTFly (Brahma and TFIID in one assembly). The coupling of Brahma and TFIID is mediated by the SAYP factor, whose evolutionarily conserved activation domain SAY can directly bind to both BAP170 subunit of Brahma and TAF5 subunit of TFIID.

SAGA and a novel Drosophila export complex anchor efficient transcription and mRNA export to NPC.

SAGA/TFTC-type multiprotein complexes play important roles in the regulation of transcription. We have investigated the importance of the nuclear positioning of a gene, its transcription and the consequent export of the nascent mRNA. We show that E(y)2 is a subunit of the SAGA/TFTC-type histone acetyl transferase complex in Drosophila and that E(y)2 concentrates at the nuclear periphery.

Two isoforms of Drosophila TRF2 are involved in embryonic development, premeiotic chromatin condensation, and proper differentiation of germ cells of both sexes.

The Drosophila TATA box-binding protein (TBP)-related factor 2 (TRF2 or TLF) was shown to control a subset of genes different from that controlled by TBP. Here, we have investigated the structure and functions of the trf2 gene. We demonstrate that it encodes two protein isoforms: the previously described 75-kDa TRF2 and a newly identified 175-kDa version in which the same sequence is preceded by a long N-terminal domain with coiled-coil motifs.

Occupancy of the Drosophila hsp70 promoter by a subset of basal transcription factors diminishes upon transcriptional activation.

The presence of general transcription factors and other coactivators at the Drosophila hsp70 gene promoter in vivo has been examined by polytene chromosome immunofluorescence and chromatin immunoprecipitation at endogenous heat-shock loci or at a hsp70 promoter-containing transgene. These studies indicate that the hsp70 promoter is already occupied by TATA-binding protein (TBP) and several TBP-associated factors (TAFs), TFIIB, TFIIF (RAP30), TFIIH (XPB), TBP-free/TAF-containg complex (GCN5 and TRRAP), and the Mediator complex subunit 13 before heat shock. After heat shock, there is a significant recruitment of the heat-shock transcription factor, RNA polymerase II, XPD, GCN5, TRRAP, or Mediator complex 13 to the hsp70 promoter.

A retrocopy of a gene can functionally displace the source gene in evolution.

The e(y)2 gene of Drosophila melanogaster encodes the ubiquitous evolutionarily conserved co-activator of RNA polymerase II that is involved in transcription regulation of a high number of genes. The Drosophila e(y)2b gene, paralogue of the e(y)2 has been found. The analysis of structure of the e(y)2, e(y)2b and its orthologues from other species reveals that the e(y)2 gene derived as a result of retroposition of the e(y)2b during Drosophila evolution.

A novel multidomain transcription coactivator SAYP can also repress transcription in heterochromatin.

Enhancers of yellow (e(y)) is a group of genetically and functionally related genes for proteins involved in transcriptional regulation. The e(y)3 gene of Drosophila considered here encodes a ubiquitous nuclear protein that has homologues in other metazoan species. The protein encoded by e(y)3, named Supporter of Activation of Yellow Protein (SAYP), contains an AT-hook, two PHD fingers, and a novel evolutionarily conserved domain with a transcriptional coactivator function.

Two different Drosophila ADA2 homologues are present in distinct GCN5 histone acetyltransferase-containing complexes.

We have isolated a novel Drosophila (d) gene coding for two distinct proteins via alternative splicing: a homologue of the yeast adaptor protein ADA2, dADA2a, and a subunit of RNA polymerase II (Pol II), dRPB4. Moreover, we have identified another gene in the Drosophila genome encoding a second ADA2 homologue (dADA2b). The two dADA2 homologues, as well as many putative ADA2 homologues from different species, all contain, in addition to the ZZ and SANT domains, several evolutionarily conserved domains.

Expression pattern of dd4, a sole member of the d4 family of transcription factors in Drosophila melanogaster.

In vertebrates, three members of the d4 gene family code for proteins, which are believed to function as transcription factors and involved in regulation of various intracellular processes. One member of the family, ubi-d4/requiem is ubiquitously expressed gene and two other, neuro-d4 and cer-d4, are expressed predominantly in the neural tissues (Nucleic Acids Res. 20 (1992) 5579; Biochim.

Rapid construction of sequencing templates by random insertion of antibiotic resistance genes.

We describe a novel and handy method for generating a population of templates for sequencing. The method is based on the random insertion of antibiotic resistance gene in plasmid DNA digested by DNase I. The advantages of this approach are the small quantity of DNA necessary for mutagenesis and the complete independence from the restriction map of the plasmid.