Role of Mod(mdg4)-67.2 Protein in Interactions between Su(Hw)-Dependent Complexes and Their Recruitment to Chromatin

• Published in: Biochemistry (Moscow) Vol. 89; no. 4; pp. 626 - 636
• Main Authors: Melnikova, Larisa S., Molodina, Varvara V., Georgiev, Pavel G., Golovnin, Anton K.
• Format: Journal Article
• Language: English
• Published: Moscow Pleiades Publishing 01.04.2024; Springer Nature B.V
• Subjects: Animals; Binding sites; Biochemistry; Biomedical and Life Sciences; Biomedicine; Bioorganic Chemistry; Chromatin; Chromatin - metabolism; Chromosomes; DNA-Binding Proteins - metabolism; Drosophila melanogaster - metabolism; Drosophila Proteins - chemistry; Drosophila Proteins - genetics; Drosophila Proteins - metabolism; Gene expression; Insulators; Life Sciences; Microbiology; Microtubule-Associated Proteins; Mutation; Nuclear Proteins - metabolism; Promoters; Protein Binding; Protein interaction; Proteins; Repressor Proteins - genetics; Repressor Proteins - metabolism; RNA-protein interactions; Su(Hw) protein; Transcription factors; Transcription Factors - metabolism; Zinc; Zinc finger proteins; Zinc Fingers; protein–protein interactions; Mod(mdg4); transcription regulation; Su(Hw); chromatin insulators
• ISSN: 0006-2979; 1608-3040
• DOI: 10.1134/S0006297924040035

Su(Hw) belongs to the class of proteins that organize chromosome architecture, determine promoter activity, and participate in formation of the boundaries/insulators between the regulatory domains. This protein contains a cluster of 12 zinc fingers of the C2H2 type, some of which are responsible for binding to the consensus site. The Su(Hw) protein forms complex with the Mod(mdg4)-67.2 and the CP190 proteins, where the last one binds to all known Drosophila insulators. To further study functioning of the Su(Hw)-dependent complexes, we used the previously described su(Hw) E8 mutation with inactive seventh zinc finger, which produces mutant protein that cannot bind to the consensus site. The present work shows that the Su(Hw) E8 protein continues to directly interact with the CP190 and Mod(mdg4)-67.2 proteins. Through interaction with Mod(mdg4)-67.2, the Su(Hw) E8 protein can be recruited into the Su(Hw)-dependent complexes formed on chromatin and enhance their insulator activity. Our results demonstrate that the Su(Hw) dependent complexes without bound DNA can be recruited to the Su(Hw) binding sites through the specific protein–protein interactions that are stabilized by Mod(mdg4)-67.2.