Drosophila Zinc Finger Protein CG9890 Is Colocalized with Chromatin Modifying and Remodeling Complexes on Gene Promoters and Involved in Transcription Regulation.

In this work, we conducted a genome-wide study of the zinc finger protein CG9890 and showed that it is localized mostly on the promoters of active genes. The CG9890 binding sites are low-nucleosome-density regions and are colocalized with the chromatin modifying and remodeling complexes SAGA and dSWI/SNF, as well as with the ORC replication complex. The CG9890 protein was shown to be involved in the regulation of the expression of some genes on the promoters of which it is located, with the ecdysone cascade genes accounting for a significant percentage of these genes. Thus, the CG9890 protein is a new member of the transcriptional network which is localized on active promoters, interacts with the main transcription and replication complexes, and is involved in the regulation of both basal and inducible transcription.

Insulator Protein Su(Hw) Is Indispensable for Amplification of Part of Drosophila Amplicons in Follicular Cells (DAFCs) during Early Oogenesis.

We found that the Su(Hw) insulator protein binds to all known Drosophila amplicons in follicular cells (DAFCs). Su(Hw) binding is required for ORC replication complex positioning on part of DAFCs during early oogenesis. Our data allow us to expand the current view on the role of the Su(Hw) protein in Drosophila oogenesis as a transcription repressor. We assume that Su(Hw) is involved in the coordination of transcription and replication processes during oogenesis in Drosophila.

Zinc Finger Protein CG9890 - New Component of ENY2-Containing Complexes of Drosophila.

In previous studies, we showed that the insulator protein Su(Hw) containing zinc finger domains interacts with the ENY2 protein and recruits the ENY2-containing complexes on Su(Hw)-dependent insulators, participating in the regulation of transcription and in the positioning of replication origins. Here, we found interaction between ENY2 and CG9890 protein, which also contains zinc finger domains. The interaction between ENY2 and CG9890 was confirmed. It was established that CG9890 protein is localized in the nucleus and interacts with the SAGA, ORC, dSWI/SNF, TFIID, and THO protein complexes.