[The Drosophila Zinc Finger Proteins Aef1 and CG10543 Are Co-Localized with SAGA, SWI/SNF, and ORC Complexes on Gene Promoters and Involved in Transcription Regulation].

In previous studies, we purified the DUB-module of the Drosophila SAGA complex and showed that a number of zinc proteins interact with it, including Aef1 and CG10543. In this work, we conducted a genome-wide study of the Aef1 and CG10543 proteins and showed that they are localized predominantly on the promoters of active genes. The binding sites of these proteins co-localize with the SAGA and dSWI/SNF chromatin modification and remodeling complexes, as well as with the ORC replication complex.

[The Drosophila Zinc Finger Protein CG9609 Interacts with the Deubiquitinating (DUB) Module of the SAGA Complex and Participates in the Regulation of Transcription].

In previous studies, we found that the zinc finger proteins Su(Hw) and CG9890 interact with the Drosophila SAGA complex and participate in the formation of the active chromatin structure and transcription regulation. In this research, we discovered the interaction of the DUB module of the SAGA complex with another zinc finger protein, CG9609. ChIP-Seq analysis was performed, and CG9609 binding sites in the Drosophila genome were identified.

[Drosophila melanogaster Paip2 Binds ENY2 and Interacts with the TREX-2 Complex in Histone mRNP Particles].

ENY2 is an evolutionarily conserved multifunctional protein and is a member of several complexes that regulate various stages of gene expression. ENY2 is a subunit of the TREX-2 complex, which is necessary for the export of bulk mRNA from the nucleus to the cytoplasm through the nuclear pores in many eukaryotes. The wide range of ENY2 functions suggests that it can also associate with other protein factors or complexes.

Xmas-2 Protein, the Core Protein of the TREX-2 mRNA Export Complex, Does not Determine the Specificity of ras2 mRNA Binding by the Complex.

The TREX-2 complex of eukaryotes is responsible for the export of a wide range of mRNAs from the nucleus to the cytoplasm. Previously, we showed that a subunit of the D. melanogaster TREX-2 complex, the PCID2 protein, has a domain that specifically interacts with RNA.

TREX-2-ORC Complex of D. melanogaster Participates in Nuclear Export of Histone mRNA.

The TREX-2-ORC protein complex of D. melanogaster is necessary for the export of the bulk of synthesized poly(A)-containing mRNA molecules from the nucleus to the cytoplasm through the nuclear pores. However, the role of this complex in the export of other types of RNA remains unknown.

The Human TREX-2 Complex Interacts with Subunits of the ORC Complex.

The TREX-2 protein complex is the key complex involved in the export of mRNA from the nucleus to the cytoplasm through the nuclear pores. Previously, a joint protein complex of TREX-2 with ORC was isolated in D. melanogaster.

PCID2 Subunit of the TREX-2 Complex Has Two RNA-Binding Regions.

PCID2 is a subunit of the TREX-2 mRNA nuclear export complex. Although the complex has long been studied in eukaryotes, it is still unclear how TREX-2 interacts with mRNA in multicellular organisms. Here, the interaction between PCID2 and the RNA was studied by EMSA.

The Xmas-2 Protein of Drosophila melanogaster Undergoes Cleavage into Two Fragments.

The TREX-2 complex integrates several stages of gene expression, such as transcriptional activation and mRNA export. In D. melanogaster, TREX-2 consists of four major proteins: Xmas-2, ENY2, PCID2, and Sem1p.

Study of the Interaction between Xmas-2, the Main Protein of TREX-2 mRNA Export Complex, and the Orc3 Protein, a Subunit of ORC Complex of D. melanogaster.

The TREX-2 protein complex is the key participant in the export of mRNA from the nucleus to the cytoplasm through the nuclear pores. Previously, a protein complex of D. melanogaster consisting of TREX-2 and ORC complexes was purified.

MLE Helicase Is a New Participant in the Transcription Regulation of the ftz-f1 Gene Encoding Nuclear Receptor in Higher Eukaryotes.

MLE helicase is an evolutionarily conserved eukaryotic protein involved in a wide range of processes in the regulation of gene expression. Previously, we studied the properties of MLE on the Drosophila melanogaster model. In the present work we continue studying the functions of MLE and show that MLE interacts with the components of the SWI/SNF chromatin remodelling complex.

PCID2, a subunit of the TREX-2 nuclear export complex, is essential for both mRNA nuclear export and its subsequent cytoplasmic trafficking.

The TREX-2 complex is essential for the general nuclear mRNA export in eukaryotes. TREX-2 interacts with the nuclear pore and transcriptional apparatus and links transcription to the mRNA export. However, it remains poorly understood how the TREX-2-dependent nuclear export is connected to the subsequent stages of mRNA trafficking.

Multifunctional ENY2 Protein Interacts with RNA Helicase MLE.

ENY2 protein of Drosophila melanogaster was previously discovered and characterized in our laboratory [1, 2]. It was found that ENY2 is a subunit of several multiprotein complexes and connects various stages of gene expression [3-5]. This work is devoted to studying the interaction of ENY2 with RNA helicase MLE.

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.

The role of SAGA coactivator complex in snRNA transcription.

The general snRNA gene transcription apparatus has been extensively studied. However, the role of coactivators in this process is far from being clearly understood. Here, we have demonstrated that the Drosophila SAGA complex interacts with the PBP complex, the key component of the snRNA gene transcription apparatus, and is present at the promoter regions of the snRNA genes transcribed by both the RNA polymerase II and RNA polymerase III (U6 snRNA).

[Protein complexes coordinating mRNA export from the nucleus into the cytoplasm].

The molecular mechanisms that coordinate transcription, processing, mRNP assembly, and mRNA export from the nucleus through nuclear pores into the cytoplasm have been the focus of intense research in recent years. Data demonstrating a tight association between the processes involved in gene expression are considered. The main protein complexes that play a role in mRNA export are described.

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.

[Methods to study the RNA-protein interactions].

RNA-binding proteins (RBPs) play an important role in regulating gene expression at the posttranscriptional level, including the steps of pre-mRNA splicing, polyadenylation, mRNA stabilization, mRNA export from the nucleus to the cytoplasm, mRNA localization, and translation. RBPs regulate these processes primarily by binding to specific sequence elements in newly synthesized or mature transcripts. While many RPBs are known to recognize certain nucleotide sequences in RNA, information is insufficient for others.

[Conservative E(y)2/Sus1 protein is the member of SAGA complex and new nuclear pore-associated complex in Drosophila].

The SGA/TFTC complex plays an important role in the regulation of transcription. We have examined the significance of the gene positioning in the nucleus for its transcription and subsequent export of nascent mRNA. It was demonstrated that E(y)2 protein was a subunit of the SAGA/TFTC histone acetyl transferase complex in Drosophila and that E(y)2 concentrated at the nuclear periphery.

[E(y)2, the novel component of SAGA/TFTC complex in eucaryotes participates in export of mRNP from nucleus and couples transcription with nuclear pore].

For many years transcription was studied independently from the following stages of gene expression. However the tight connection between different stages of gene expression became evident during the last years. This review discusses the new molecular mechanisms coordinating transcription and mRNA export from the nucleus and coupling of transcription and position of the gene in the nucleus.

[Conservative E(y)2/Sus1 protein interacts with the Su(Hw)-dependent insulators in Drosophila].

Insulators are regulatory elements having two properties. First, they are able to disturb the interaction between promoters and enhancers/silencers. Second, they are able to block distribution of the heterochromatin.

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.

Evolutionarily conserved E(y)2/Sus1 protein is essential for the barrier activity of Su(Hw)-dependent insulators in Drosophila.

Chromatin insulators affect interactions between promoters and enhancers/silencers and function as barriers for spreading of repressive chromatin. The Su(Hw) protein is responsible for activity of the best-studied Drosophila insulators. Here we demonstrate that an evolutionarily conserved protein, E(y)2/Sus1, is recruited to the Su(Hw) insulators via binding to the zinc-finger domain of Su(Hw).

Integrity of the Mod(mdg4)-67.2 BTB domain is critical to insulator function in Drosophila melanogaster.

The Drosophila gypsy insulator contains binding sites for the Suppressor of Hairy-wing [Su(Hw)] protein. Enhancer and silencer blocking require Su(Hw) recruitment of Mod(mdg4)-67.2, a BTB/POZ domain protein that interacts with Su(Hw) through a carboxyl-terminal acidic domain.

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.