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.

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.

Nonreplicative functions of the origin recognition complex.

Origin recognition complex (ORC), a heteromeric six-subunit complex, is the central component of the eukaryotic pre-replication complex. Recent data from yeast, frogs, flies and mammals present compelling evidence that ORC and its individual subunits have nonreplicative functions as well. The majority of these functions, such as heterochromatin formation, chromosome condensation, and segregation are dependent on ORC-DNA interactions.

Telomeric repeat silencing in germ cells is essential for early development in Drosophila.

The germline-specific role of telomeres consists of chromosome end elongation and proper chromosome segregation during early developmental stages. Despite the crucial role of telomeres in germ cells, little is known about telomere biology in the germline. We analyzed telomere homeostasis in the Drosophila female germline and early embryos.

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.

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.

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.